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“That’s the rankest psychologism, and was conclusively revealed as hogwash by Gottlob Frege in the 1890s!”
― Sheldon Cooper

“In Frege’s conception of logic, a logical law states an absolutely general truth—one whose truth every rational being must, on pain of contradiction, acknowledge. In later Wittgenstein’s practice, a grammatical remark inherits an aspect of Frege’s conception of the logical. On a proper understanding of a grammatical remark, it articulates a truismâ€� something that admits of no contrary—hence something that every speaker of the language must acknowledge. Or conversely, if there is something in a given candidate grammatical remark that proves to admit of disagreement, then the remark in question cannot serve its methodological role. It fails to bring into view a point of (what later Wittgenstein calls) grammar. Grammatical remarks acquire their point—that is, our need for such reminders derives—from our attempting but failing to achieve a proper reflective understanding of our way around our own language. If the grammatical remark serves its purpose, what is thereby acknowledged is something that can come into view only against the background of a prior failed attempt to achieve a perspicuous overview of our own concepts. A Wittgensteinian grammatical remark comes to life as such only against the background of a philosophical confusion. Logic or grammar for later Wittgenstein, pace Frege, could qualify as a science only if philosophy is one. This also means that, for later Wittgenstein, unlike for Frege, there is no preexisting stock of propositions that constitutes all of the logico-grammatical truths there are. In potentiality there are perhaps indefinitely many, but in actuality the only remarks that actually exercise the power to disclose a philosophico-grammatical truth, for later Wittgenstein, are those that allow us to make progress with the problems that actually vex us in philosophy.”
― James Conant, The Logical Alien: Conant and His Critics

“How does one do justice to what occasions philosophical wonder in us without conferring false sublimity upon it? We said that what occasions Frege’s wonder—the absoluteness of the logical order—seems to him to be such that it cannot possibly be implicated in our dependence upon language: say, in our meaning to assert p in using a proposition to say one thing rather than another, or in our using just these words rather than some others to assert it. The Tractatus (while repudiating Frege’s conception that the nature of logic may in no way be implicated in that of language) still seeks a way to hold onto the idea that in logic it is not we who express, by means of signs, what we want; rather it is the nature of the essentially necessary signs—it is logic—that asserts itself. The later Wittgenstein, as we are about to see, seeks to undo this residual subliming of the logical in the Tractatus, while in no way seeking to dissipate the sense of wonder at the illimitable depth of the logicalâ€�(what he later calls) the grammatical—that shows itself in our forms of thought and life.”
― James Conant, The Logical Alien: Conant and His Critics

“For Frege, an account of what it is for a purely logical power to be in act suffices to allow us to achieve a proper philosophical appreciation of what “content,â€� “object,â€� “thought,â€� “judgment,â€� and “truth,â€� as such, are. These notions come to be fully in place through an elucidation of that power, considered apart from our capacity to arrive at kinds of knowledge that are not purely logical in content. Our capacity for empirical judgment, when it comes into view, will come into view as a comparatively complex joint exercise of a variety of faculties, in which the logically fundamental notions that figure in its explication (“content,â€� “object,â€� thought,â€� “judgment,â€� “truthâ€�) are still supposed to retain the specific sense originally conferred upon them in our explication of the purely logical case, while allowing for their extension to logically impure cases of thought and proposition.
A certain picture of the role of reflection on the purely logical case, inthe order of explication of kinds of knowledge, is at work here—a picture that has been enormously influential on the subsequent development of analytic philosophy. On this picture, only if we are armed with a prior account of the case of purely logical thought, supplementing it as we go along, can we come to understand what empirically contentful theoretical thought (or practical thought) is. On this picture, the spatiotemporal bearing and the self-consciousness of the thinking subject do not belong to the form of thought (and hence their treatment does not belong, as Kant held, to a suitably capacious conception of philosophical logic); rather, all such further details among various species of thought are to be subsequently specified, if at all, through the introduction of further indices figuring within the content of thought. (Thoughts are simply conceived of as occurring at a time or at a person.) These consequences of the Fregean picture are not, on the whole, something for which post-Fregean analytic philosophers argue. Rather, it involves an entire philosophical picture that is simply tacitly, and largely unwittingly, assumed—a picture that is already under attack, albeit in very different ways, in both Kant and early Wittgenstein. According to this post-Fregean picture, we can furnish an account of the wider reaches of our capacity for finite theoretical cognition only by assuming the prior intelligibility of some self- standing account of how one of the ingredient capacities in empirical cognition—the capacity for logical thought—off its own bat is able to yield a delimitable sphere of truth-evaluable, object-related thoughts with judgable content, without its yet having entered into any form of co- operation with our other cognitive capacities.”
― James Conant, The Logical Alien: Conant and His Critics