Mortimer Adler Again

From The Four Dimensions of Philosophy: "A sound approach to the examination of knowledge should acknowledge the existence of some knowledge to be examined. Knowing what can be known is prior to asking how we know what we know.
Using the word "epistemology" for the theory of knowledge-especially for inquiries concerning the "origin, certainty, and extent" of our knowledge-I have two things to say about this part of the philosophical enterprise.
First, it should be reflexive; that is, it should examine the knowledge that we do have; it should be a knowing about our knowing.
Second, being reflexive, epistemology should be posterior to metaphysics, the philosophy of nature, ethics and political theory-these and all other branches of first order philosophical knowledge; in other words, our knowing what can be known should take precedence over our knowing about our knowing.
Both of these procedural points were violated in the movement that began with Locke and ran to Kant. Epistemology became "first philosophy", taking precedence over all other branches of philosophical inquiry; and with Kant, it became the basis for "prolegomena to any future metaphysic."
Epistemology more and more tended to swallow up the whole philosophical enterprise. It is this retreat from the known world and our knowledge of it to the world of the knower and his efforts to know which prepared the way for the later retreat of philosophy (in our own century) to the plane of second order questions, relinquishing entirely any claim to have a respectable method for carrying on first order inquiries.
I think it is apt, and not too harsh, to call this first unfortunate result of the critical reaction to dogmatic systems "suicidal epistemologizing." Epistemology, fashioned by philosophers as a scalpel to cut away the cancer of dogmatism, was turned into a dagger and plunged into philosophy's vitals.
The second unfortunate result can, with equally good reason, be called "suicidal psychologizing". Like the first, it is also a retreat from reality. Where the first is a retreat from the reality of the knowledge that we actually do have, the second is a retreat from the reality of the world to be known. Modern idealism begins with Kant. It is the worst of the modern errors in philosophy.
What I mean by "suicidal psycholgizing"is sometimes less picturesquely described as "the way of ideas," fathered by Descartes, but given its most unfortunate effects by the so-called British empiricists - Locke, Berkeley, and Hume - who made the psycholgizing of common experience the whole of philosophy and substituted that for the use of common experience as a test of the soundness of philosophical theories or conclusions about the experienced world. The psycholgizing of common experience deserves to be called suicidal; for in effect, it cuts away the very ground on which the philosopher stands. It makes experience subjective, rather than objective."