¶ … Substance According to John Locke John Locke along with the likes of Berkley and Hume was a British Empiricist. He was of the theory that all knowledge was based on sensory experience of some sort and in his "An Essay Concerning Human Understanding" (1690) he attempted to try to explain the basis of his theory in detail. Complications arose because Locke's logically derived and systematic conclusions could not fit a solely material and objective mold in which he tried to fit knowledge. In the era when scientific advances and evidence-based knowledge was coming to the fore Locke investigated methodically the basic materials and human acquisitions of them to produce knowledge or ideas. It was when he inevitable entered the realm of feeling, spirituality, and the improvable that his epistemological theory started showing signs of hole. When it came to defining 'substance' he confused and contradicted himself because he could neither prove it materially nor deny it logically if anything that was anything was to make sense.

According to Locke's explanation the only parts of human knowledge that objectively exist and are actually real and unchanging are qualities, specifically primary qualities. These he listed as "bulk, figure, text, and motion." [Locke 1974] He didn't state that these were the only ones, just the ones he presumed important. Secondary qualities were combinations of primary ones and subject to variation from individual to individual. These included such entities as color, smell, or taste, etc. For example two people may agree that a certain carpet is flat and square but may vary in their opinions of its softness, quality of blue thread used all depending on visual and tactile acuity and opinion.

Locke postulated that together primary and secondary qualities stimulated the minds by sensory experience to produce simple ideas such as 'the color red.' These simple...

Complex ideas are combinations of simple ideas. Simple ideas can be compared, relationships identified, or they can be sorted into categories according to similarity. This last way of forming complex ideas is "abstraction," and this is what we are doing when we give a name to a substance, like "apple" or "gold."[Randall 1997] Thus he argues there is no such thing as "innate knowledge" or original thought. [Locke 1974]
Simple ideas cannot be broken down into simpler forms and include a uniform perception such as that of 'redness.' This redness does not necessarily have a given form and just is. It cannot be perceived objectively as redness does not exist without some form or substance in the material world, at least as far as we know. [Randall 1997] According to Locke, qualities "cannot be imagined to [i.e. It is inconceivable that they] subsist by themselves." [Locke 1974] The substratum wherein these qualities were perceived to exist was defined as 'substance.' The difficulty was in proving objectively what exactly this 'substance' was though all logical thought pointed to the fact that it must exist. However Locke's own theory stating all knowledge was based on experience and thus must first be perceived by the senses contradicted the characteristic of 'substance' being unperceived.[Randall 1997] Thus if Locke was right substance must also logically not exist![Randall 1997]

The problem with the concept of 'substance' is that it eludes explanation through words and slips through the mind's fingers just when one thinks he has grasped it. Locke calls the idea of substance "obscure" [Locke 1974] yet insists on using it stating that it must exist though we will never be able to define or prove it. To any scholar of knowledge such a conclusion would be unacceptable but in his confusion Locke apparently did…