Explicates European philosophy from Descartes to Wittgenstein: modern pursuits commenced with the identification of the subject, were borne along by detachment of the object, and concluded when the subject became knowable in light of the object. As in phenomenology, the author treats the big questions as regarding certainty and doubt.

To be part of the history of philosophy, an idea must have been significant in the train of philosophic thought, whereas history of ideas is concerned only with an idea’s influence on human affairs, for what distinguishes philosophic thought is its primary concern with possibility, necessity, and truth (validity), not actuality.

Dispute over universals was an important distinction between empiricism and rationalism, the measurable / demonstrable versus the deductible. This in turn pointed up the importance of language. Abstraction, the concern of practical methodology prior to modernity, turned on either Platonic objects or intellectual criticism of methodology.

Bacon rejected Aristotelian deduction in favor of induction, and postulated universal laws based on observed instances, marrying empirical and rational. This ended scholasticism and paved the way for Descartes. (The ontological argument that God is proven because no greater entity can be held from Aristotle through St Anselm though the medieval schoolmen naturally favored Platonic ideas versus skepticism.) The Frenchman held human knowledge is a tree, the trunk being physics and the roots metaphysics. Philosophy ought to commence with a method of doubt in order to arrive at undoubted propositions. These must be at least as much real in cause as effect (cosmology versus ontology). This radical break with scholasticism renewed both rationalism and empiricism. Not the Renaissance but the birth of modern philosophy in the early 17th century is the origin of the modern West. Science and philosophy went hand in hand. Descartes sought for fundamental laws so general as to explain all, yet a prior (i.e., not demonstrable by experiment), deductively departing from metaphysics.

Spinoza: the more active a man in respect of behavior, the more his consciousness understands cause. The more man grasps the cause of causes, the more free he is. Leibniz’s rationalism turns on the principle of contradiction (that which opposes false is true) and the principle of sufficient reason (for every truth there is a threshold of evidence that’s enough). Rationalism assumes man possesses ideas which outstrip experience (e.g., God, cause, self). The existence of innate ideas is not necessary for language, as Locke showed: possession of a concept does not equal the power to acquire it. Locke (tabula rasa) and Leibniz (monads) were arguing over the possibility of a priori ideas. Shaftesbury thought love of beauty is animated by perception of happiness, which is much the same as the tendency to admire virtue (in others). Bishop Joseph Butler asserted, borrowing from Cicero, the distinction between power and authority: conscience is a steady force that is both maker of law (common to men) and provider of notice to obedience. There is no such thing as a love of injustice or oppression. Hume’s naturalism (i.e., close connection with human nature) led to preferring custom over reason whenever choice is not obvious. Skepticism is more empirical use of reason than deductive, reason being the subordinate of passions; if reason were superordinate, we would be driven to radical skepticism whenever reason had no competence. Thus reason should cede to custom, the exemplar of human nature. The Philosophes were rooted in Cartesian skepticism, born of metaphysics, but added nothing to philosophy: theirs was more polemics, to ridicule rather than generate new understandings.

Kant asserted the legitimacy of rational deduction (including its limits). Skepticism doesn’t hold because deduction allows for understanding the object, and the principles of science allow for a priori knowledge. Science is a posteriori, based in experience, but rests on axioms and principles which cannot be demonstrated, what he called synthetic a priori or necessary truth. Neither empiricism nor rationalism provides a coherent theory of knowledge, which is achieved through the synthesis of concept and experience, and which synthesis can never be observed as a process but must be presupposed as a result. ‘Transcendental’ means to overcome through rationalization what argument must presuppose. Experience conforms to ‘categories’ of understanding which are a priori (e.g., table < artifact < object < substance). Kant like Descartes begins from self-consciousness but rejects the priority of the first person (subjectivity), which precludes empiricist epistemology. Metaphysics is superior to epistemology, because the former enables the senses to deliver. The tendency of reason to outstrip intelligibility is the dialectic of reason, a concept which influenced Hegel. Kant revived the ancient distinction between theoretical and practical reason, setting the stage for German idealism. Theoretical (pure) reason guides belief, practical reason guides action. The former aims at truth, the latter at rightness. The former can lead to understanding or standing on reason; however practical reason, being a judgment of imperatives (i.e., objective conditions), does not automatically generate morality. This points to the categorical imperative, the universal, unconditional treatment of humans as ends in themselves. The idea conclusively undermines Hume’s skepticism, since reason is no longer inert, subject to desire: the moral law is not only universal but necessary, for there’s no way of practical thinking can ignore these features. This is a priori – but Kant left open a gap in metaphysics and ethics by omitting proof of objective necessity – practical reason cannot demonstrate how things are (e.g., that God exists or the soul is immortal) but only how things ought to be. No moral law is intelligible without freedom; to act in concert with the law out of coercion does not prove the law, but the actor must choose to comply from the premise of reason, conscious of his autonomy. No one has argued more for the objectivity of morality, but Kant’s aesthetics, which form a picture of relation of the mind to experience, accommodates subjectivity. Morality cannot be observed by experience but must be treated as so because of the ‘pressure of reason’. Fichte thought understanding knowledge is a free, self-producing object which knows itself by determining itself, realizing freedom in an objective world. This view of venturing outward, alienating the self (that is, thesis-antithesis), to emerge with synthetic self-consciousness and understanding of order, runs through Hegel, Marx, Heidegger, and others. Hegel sought to replace Aristotelian logic by starting not from the structure of argument but the nature of being: logic is not preserving truth (formality) but telling what truth is (substance). (Modern logic advanced so as to set both aside, by adopting conditionality.) While Kant saw the dialectic as propensity to fall into contradictions, for Hegel it was the likelihood of surmounting them. Concepts are true or false. The historical process is dialectic, but is logic a science of relations among ideas, or an intellectual operation whose relations are to be discovered? (The character of any ontological proof is demonstrated in procession from concept to reality.) Hegel’s genius for abstraction inevitably leads away from subject of thought to thought itself, resulting in metaphysical blurring of the distinction between thought and reality – the principal characteristic of idealism. Hegel tries to show knowledge of the self as the subject presupposes not only knowledge of objects but also knowledge of the public (social) world which possesses moral order and civic trust - that is, the basis of the categorical imperative. This re-abolishes Kant’s separation of practical and theoretical wisdom, since the subject is not constrained to acknowledge the other (the object). The real subject, as in the phenomenological view, is Geist not the solipsistic self. Hegel’s metaphysics is largely independent of epistemology, avoiding Descartes’ first person. The dialectic of reason works through ontology: nothing exists which is not pure being, derived from rational synthesis of concept. The ‘cunning of reason’ is the world discovering that the seemingly contingent is in fact necessary – the real is rational, the rational real. Consequences in history, politics, art criticism and so on have been disastrous. Hegel was truly a philosopher of modernity, though like Bertrand Russell, who saw only exterior of thought, missed the import of the profound spiritual crisis which he sought to describe, the crisis of a society newly understanding God was its own creation. Schopenhauer: one’s self-awareness consists of knowing one’s own will, but only as a phenomenon, that is, in a given space and time. Though disappointed w Hegel’s popularity, he made Kant’s system more understandable: it jibed with Romanticism and Christian Germany, and prefigured Wagner and Nietzsche, who chose will over resignation, thereby foreclosing romanticism in Germany philosophy. Kierkegaard criticized Hegel for transferring religious faith from Christian god to philosophy of history. This was a necessary outcome but false because logic, the science of inference, cannot provide its own premises and also the Hegelian universal subject is in fact the absence of subject. Kierkegaard moved back toward the Cartesian subject. Nietzsche, despite a very different style, was highly Aristotelian, seeing good in ordering passions the right way, into self-mastery; these were not located in religion. Trying to forestall nihilism, not to promote it, his radical critique of identifying the ‘will to believe’ in orthodoxy has been beloved of the West’s leftist critics. Hobbes’ assertion that man’s obligations to political society stem from himself is the most important idea promoted by the philosophes. Rousseau’s general will comes about from men coming into civil society: it is not the will of all, though notoriously it can force men to be free. One of Hegel’s most important innovations in political thought is the state as an entity (as compared with civil society). He denied the social contract: individual autonomy can only be defined in reference to society. His civic obligations stem from piety to the polis, and the individual finds freedom in self-discovery commencing with the family (itself another innovation – recognizing a private institution as a political but also not contractual). Marx thought the nature of man isn’t fixed but laws are intended, like property, to be permanent, thus discouraging fluidity (toward the ends of equality) in social relations and ensuring the subject’s alienation from the self. This is laid out in German Ideology, which seeks to undermine the moral and political order of capitalism. Alienation (false consciousness) is necessary to correct errors of perception in the social world. Ultimately the nature of man, the movement (philosophy) of history, and the conception of economic value are each attempts to define what determines man’s consciousness. They are all material (substantive) and social, and all ‘labor’ in that this is the heart of a political philosophy which sees the common man as supporting the superstructure of society (i.e., the labor theory of value). Burke’s roots were in the moral psychology of the 18th century. The Utilitarians were fundamentally concerned with the nature of political freedom, but the concept of the rational agent, present from Plato to Kant, disappears in the ‘greatest good for greatest number’ formulation. Mill demonstrated the difference between logic and science in distinguishing between deduction and induction. His individual is anarchic, subject to impulse, and lacking the north star of freedom, as Arnold’s Culture and Anarchy pointed out. The practical response is embodied in the British idealism of FH Bradley, who saw the individual inherently operating in a social milieu. Since Kant assigned metaphysics to synthetic a priori, giving math as the preeminent exemplar, Frege’s demonstration that math is analytic opened the way for the modern rejection of metaphysical argument. Frege, who had overturned Aristotelian, syllogistic logic, showed math is not concerned with the properties of objects but the second-order properties of properties of objects, vindicating the Kantian assertion that existence is not an Aristotelian predicate. Statements of identity are not statements which predicate the property of an object. Venus is the morning star can be reversed, but Socrates is wise cannot, so the distinction between subject and predicate is the ability to assign properties to the object (otherwise everything is an arbitrary determination). Frege’s views allow for extension (i.e., truth value) and intention (truth conditions) in sentences. Extensions are detachable, and so independent existence is possible for objects. Phenomenology, credited mainly to Husserl, is the necessary preliminary to science of the mind – psychology – since it locates prior to description, classification, or explanation in the individual’s mental acts. It is the access to meaning created by these acts, the world becoming present to individual consciousness. Phenomenology is the understanding of essences, therefore an a priori science. Hermeneutics searches for reasons not causes, understanding texts as expression of the creator’s rational activity (i.e., understandings of the author’s intentions better than he does). The classifications aren’t scientific, are not disprovable, and so an axiomatic authority. Husserl’s work revived efforts to distinguish between human real (of meaning) from the natural realm (science); his Lebenswelt showed science had invaded where its power is groundless, but nonetheless results in a moral vacuum, for Lebenswelt collapses when not sustained by reflection on human matters. Of the existentialists, Heidegger was most concerned to counter the role of science, addressing time in the Kantian notion of the form of an inner sense. Satre would later pick up the thread, both he and Heidegger following Hegel in complicated means of distinguishing things from persons. Heidegger addressed the modern problem of self-knowledge via ontology, based on self-consciousness. After him, philosophy’s detour from logic, metaphysics, and epistemology allowed it to (again) stray into the psychology: moral exhibitionism is logical end of existentialism. Satre, following suit, proposed existence precedes essence: there is no human nature, since there’s no God to have conceived nature; essences vanish with the human mind that created them. Descartes cogito is transformed by Husserl’s phenomenology: all consciousness is intentional, the subject-object relation arises in ways that defy common-sense description. Sartre introduced nothingness as an entity, making logical mistakes and consequently forcing him to strain language. Like Socrates, his discussion (e.g., of Pierre not being in a café) introduces aporia. He leads to the inability to distinguish objects from subjects, an anguished path to ethical subjectivism. Any attempt to establish a system of values represents an attempt to transfer individual freedom to the objective world, which is to cede freedom for nothing, since there is no valid order. Sartre seeks to preserve Kant’s ethic of moral autonomy while divesting it o commitment to a moral law: he cannot transcend the impasse of paradox and dialectics. Wittgenstein, who concluded Heidegger evidenced a ‘bewitchment of intelligence’ in his use of (convoluted) language, was the most important philosopher of the 20th century. He saw truth as extension that is vital to logic and analysis. Logic must be transparent, while analysis (analytical philosophy) assumes the surface form of language to contain hidden logical structures. His philosophy ended the tradition of inquiry premised on the subject which started with Descartes, refuting the possibility of pure phenomenology, since nothing can be learned from the study of the first person alone (Cartesian examination). The first person distinction between being and seeming collapses, nothing can be certain, only a common public language determining first-person ‘knowledge’: I know things because others agree the premise. The condition of self-knowledge is a knowledge of others; the third person takes priority. The first person certainty of Descartes (rationalism) and Hume (empiricism) had been displaced, and with it modern epistemology and metaphysics. The ambitions of Kant and Hegel to remove the self from the core of knowledge have been achieved. What is the relation between logic and dialectics (science of deduction)? NB: Bertrand Russell thought the worse one’s logic, the more interested the consequences.