Philosophy must develop a method distinctly its own. Philosophy must not be esoteric and out of touch with the real world. To Adler knowledge is truth beyond the shadow of a doubt. Philosophy is like mathematics to Adler, in that it is non-investigative. In other words math can be developed without special equipment to conduct investigations.
Philosophy is also like math because it deals with ideal objects, objects of thought.
This is because philosophy is based on synthetic judgments in contrast to analytical judgments. Philosophy is like common sense it is acquired by intellectual insights and rational thought processes. It cannot be too often repeated that philosophy is everbody's business. To be a human being is to be endowed with he proclivity to philosophize. This means knowledge about reality.