Hume as an empiricist denied all innate ideas with the argument that all our knowledge comes from sense experience claiming that at birth, man‟s brain is a “tabula rasa” until through sense experience in the form of sense perception, it begins to register things. His argument was that if there were something like innate ideas, all men should know and it becomes a universal knowledge. However to Hume, one cannot have knowledge of anything except through experience, there is no possibility of getting knowledge of anything unless through sense experience. He claimed that “if some new objects be presented to a man of strong natural reason and faculties, as this object is entirely new to him, he can never, by the most accurate examination of sensible examination of sensible qualities be able to discover any of its causes or effect.”33 Hume believed that a priori propositions is analytic in the sense that it does not express a synthetic connection between two distinct things or notions but only as an analysis into its components of the entity or notion expressed by its subject.
Hume and other empiricist unjustified denial of innate ideas according to Umeogu should
197 not warrant them to claim that the principle of empiricism must govern our knowledge of reality. This position of Hume and other empiricists jeopardized the establishment of knowledge that is absolute.
The denial of innate ideas has undergraded or even annihilated in the words of Umeogu the a priori aspect of knowledge and this led Hume to become exclusively inductive “even to the uncomfortable context of, at times, sensualizing intellectual concepts”34 Hume‟s position only spelt out that there may be innate ideas and not that the principles of empiricism must govern human knowledge or reality. For Hume and other empiricists, propositions do not give us any new knowledge but merely express what we already know.
However, the locus standi and mode of explanation of Hume and the empiricists in general is found to be responsible for the inconsistency found in their theories; this actually led to their wrong usage of concepts/terms like, idea, substance (which some knew not what of), cause, principles, space, time, perception etc. This conclusion stemmed from the fact that Hume and other empiricists cannot by their empiricist principles be able to provide a conclusion foundation for universal or necessary idea or ideas concerning entities that are unobservable. This is evident in this quote that “…mere phenomenal similarity or the imaginative association of ideas is not profound enough to uphold any necessity or universality.”35
Further,
198 Knowledge concerning the future is unattainable because observation
merely informs us about the past, predicative knowledge can only be constructed by inferential methods, but since the implication leading from past to future observation is synthetic, deductive inference cannot be applied to the derivation of statements about the future, and the only instrument of prediction is the inductive inferences. And since the inductive inference can neither be validated by deductive logic nor by reference to experience, we have no reason to accept it; the inductive inference (thus) appears unjustifiable. Empirical methods (accordingly) cannot establish knowledge.36
Moreover, we cannot know whether there is any conformity with our system of explanation, descriptions and all to/with reality, going by the contention of Hume and his group as there is evidently no determinate comparison given the principle of empiricism.
From all that has been said so far, one can detect that Hume‟s empiricist position and the position of the empiricists in general of taking sense perception (in the form of having impressions and ideas) to be the only source of knowledge cannot conclusively provide a theory-free basis for knowledge; observation claims being theory laden and theory-infected must at all events always derive their credibility, meaning and justification from non-observational theory or network of background assumptions. All of these boiled down to the justified claim that a system of theory must be logically and factually consistent and must be of composite of both frame and stuff aspect to be consistent and meaningful. Knowledge inversely comprises of both the reason and sense experience to apprehend knowledge in totality. Hume and his group failed in recognizing the frame aspect of knowledge and this is the reason Umeogu‟s idea of philosophical consistency held Hume‟s empiricism as inconsistent and so, erroneous; for according to Umeogu, “a position which is logically and/or factually inconsistent is an unfailing product of error.”37
199 Hume‟s contention that the only way to certain, whole and indubitable knowledge is through sense experience is wrong in the sense that knowledge of sense experience (stuff) without reason (frame) is not enough; this is to say that “without the organizing and conceptualizing power of reason, sense data would remain momentary and unrelated impressions.”38
The empiricists (Hume not excluded) clarified that the “truths of reason” are dependent on
“truths of facts” because the “truths of reason” are not innate; the proof of this is that all men are not aware of possessing these infallible innate truths. However Hume and other empiricists may want to prove this, sense perception certainly and undoubtedly needs the assistance of reason to supply meaningfulness to what the sense data has supplied by the senses.
From the submissions above, one cannot but accept the fact that both experience and reason complement each other in knowledge acquisition.