(a) Does the rejection of metaphysics as proposed by Logical Positivists relate to problem of meaning or problem of knowledge or…

(a) Logical Positivism and the rejection of metaphysics

The rejection is first a claim about meaning, and from it follow consequences for knowledge and for the nature of things. Meaning. The Vienna Circle (Schlick, Carnap) and A. J. Ayer (Language, Truth and Logic) hold that a statement is cognitively meaningful only if it is analytic (logic and mathematics) or empirically verifiable. Ayer separates strong verification (conclusive) from weak verification (some experience would make it probable). "The Absolute is perfect" and "God exists" are neither, so they are not false but meaningless pseudo-statements; Carnap's example is Heidegger's "the Nothing nothings". Knowledge. Knowledge is confined to sense experience and logical tautology; a priori knowledge of reality is impossible. The synthetic a priori of Kant is denied, and ethics and theology become emotive expressions. Nature of things. Positivism offers no rival ontology, such as materialism; questions about substance, the Absolute or the thing-in-itself are pseudo-problems resting on misuse of language. Philosophy becomes logical analysis of language, the linguistic turn. So the rejection touches all three, with meaning as its ground. Criticism: the verification principle is itself neither analytic nor empirical; scientific laws and statements about the past are hard to verify; Popper proposed falsifiability, and Quine denied the analytic-synthetic divide.

(b) Bracketing and reduction in Husserl's method

Husserl made philosophy a presuppositionless rigorous science, going back "to the things themselves", against psychologism and naturalism. Epoché (bracketing, Einklammerung) suspends the natural attitude, the naive belief that the world exists independently. It is not Cartesian doubt or denial: the world is not rejected but its existence is put out of play, so that what is given is studied as it is given. Eidetic reduction removes contingent facts by free imaginative variation to reach essences (eidos), for example the essence of a perception. Transcendental reduction turns from the empirical, psychological ego to pure consciousness, the phenomenological residue that remains, the transcendental ego. Significance: it gives an absolutely certain basis for knowledge and opens the field of intentionality, the correlation of noesis and noema, in which the meaning of the world is constituted by consciousness. The method is set out in the Ideas and the Cartesian Meditations. Critics, including Heidegger and Sartre, held that it leads to idealism and loses the worldly, embodied subject.

(c) Sartre's conception of consciousness

In Being and Nothingness Sartre distinguishes the in-itself (en-soi), solid, opaque and identical with itself, from the for-itself (pour-soi), consciousness. Consciousness is intentional: always consciousness of something other than itself, with no content of its own, so it is a nothingness (néant). "It is what it is not": consciousness is its possibilities and projects, which do not yet exist, so it is always ahead of itself. "It is not what it is": it escapes its past and facticity by nihilation; a person is not simply what he was or what others say he is. Features that follow: Consciousness is pre-reflective self-awareness (the pre-reflective cogito), not a substantial self; the ego is an object for consciousness. Consciousness is freedom without a fixed essence, so existence precedes essence, and humans are "condemned to be free", with anguish. Escape from this is bad faith (mauvaise foi), as with the waiter who plays at being a waiter. Through the look (le regard) of the Other, I become an object, which introduces conflict into relations with others.