James Mark Baldwin, answered from the texts and cited to the page.
Genetic epistemology is the inquiry into how knowledge arises — not what knowledge is in its finished, static form, but through what stages and by what processes it comes to be. The philosopher who takes a cross-section of the knowing mind and calls that a theory of knowledge has described the fruit without asking how the tree grew; the genetic epistemologist refuses that shortcut.
The core claim is this: a category of thought — substance, cause, self, number, truth — is not an eternal form given in advance to the mind, nor a brute datum of experience. It is a habit, broadly defined as a disposition to treat items of experience in certain general ways, and like any habit it has a history of formation.1 These habits or categories arise either from actual accommodations made in the course of experience, with functional utility selecting what persists, or from natural endowment secured by variation and selection across generations.2
To know what a category is, then, you must trace the process by which it was formed; the finished logical structure is the last term of a genetic series, not its presupposition. The method that follows from this is one of tracing meanings of reality as consciousness itself reaches them — following the external reference of knowledge and the inward sphere of existence through their transformations from simpler to more complex stages of mental development.3
At each stage, what counts as real, what counts as known, what counts as true, is itself a product of the development already accomplished; and the movement is one of constant redistribution between what I called the inner and the outer controls, the assimilating self over against the presented, confirmable, objective world.4 Neither pole is fixed; both are remoulded as the development proceeds.
What I denominated Genetic Logic treats thinking as a living, working principle in the world — not the logician's abstract calculus of forms, nor the metaphysician's timeless system, but the knower's actual operation by which he comes into valid apprehension of the world and reacts upon it.5 It is genetic because it does not deny the progressive movement that mind and nature together show; it follows that movement rather than abstracting away from it.
The exact or agenetic sciences succeed precisely by selecting only those aspects of things that repeat, that submit to quantitative analysis — and their very success is evidence that no genuinely genetic movement has been captured in their formulae.6 Genetic epistemology takes up what they leave out: the adaptive, the novel, the developmental.
Truth and value, on this view, are not separate kingdoms governed by separate logics; they share a process of mediation through ideas, and the genetic method applies to both.7 The aesthetic mode — the imaginative or semblant function — turns out to be, at each stage of development, the point where the dualisms of inner and outer control find their provisional reconciliation; and so the genetic method must be extended to that mode as well, tracing it through the entire course of mental development.8
a category is a mental habit; that is all a category can be allowed to be — a habit broadly defined as a disposition, whether congenital or acquired, to act upon, or to treat, items of any sort in certain general ways.Development and Evolution
These habits or categories arise either from actual accommodations with 'functional' or some other form of utility selection, or by natural endowment secured by selection from variations.Development and Evolution
We are to inquire as to the rise and progress of meanings of reality, as consciousness itself reaches them. The external reference of knowledge and the inward sphere of existence, each illustrating one of the great factors of control, are traced through their transformations from simpler to more complex stages of mental development.Thought and Things Vol 3 Real Logic
We find, through the course of mental development, a growing mass of assimilating, acknowledging and intending process, calling itself the ego or self, over against a fairly stable, presented, recognized body of objective stuff... The whole movement is seen to be one of constant redistribution, under the relative dominance, for consciousness itself, of one or other of these two factors, called inner and outer 'controls.'Thought and Things Vol 3 Real Logic
It treats Thinking as a living, working principle in the world, doing the work it is meant to do... It is, therefore, not the 'Logician's Logic,' nor yet the 'Metaphysician's Logic'; but it is truly, and in the first place, the 'Knower's Logic' — the normal operation of that function by which the knower comes into what for him is valid apprehension of the world.Thought and Things Vol 1 Functional Logic
the success of the quantitative and analytic methods is itself the evidence that no really genetic movement has occurred out of the natural aspects of things; in other words, only those have been taken which illustrate the repetitions, not the adaptations, of nature.Development and Evolution
this leads us to place truth and value together, as having a logic — a process of mediation through ideas — in common.Thought and Things Vol 3 Real Logic
The immediacy of the aesthetic type is traced and found to be, throughout the entire course of mental development, the solvent of the dualisms created by the partial motives of cognitive and practical interest in working themselves out.Thought and Things Vol 3 Real Logic