Empiricism

The issue with the question of whether or not all of our knowledge comes from the use of our senses has more to do with the word all rather than the entire question. I don't think there is any argument that a vast amount of our knowledge is gained by the usage of our senses. However, I think that it is problematic to say that all of our knowledge is gained in this fashion. Many areas of knowledge seem to support the theory of knowledge gleaned from senses. Art relies entirely on sensory perception, for example.

Knowledge is something that is understood after we are able to see a connection between a concept and reality (barring the question of what is real and what is not real since that presents a whole other issue altogether!).

I can know that 2+2=4 either from memorization of formulas early in childhood and acceptance of these formulas as fact or from accessing this equation from a knowledge base. However, if someone were to come up to me and ask me for 4 kumquats, my previous knowledge of 4 does me absolutely no good since I may not have any clue as to what a kumquat is or how a kumquat has anything to do with the concept of 4 or even what the concept of 4 really means! I would have to break down that initial concept of 2+2=4 to eventually get to the point where I am able to relate that number of 4 to a quantity that I can then physically count and handle and relate to a barrel of kumquats. I think this is why mathematics is far more complex and goes beyond the initial idea in this post that all knowledge comes from the use of our senses. We may use our senses to understand and apply mathematical knowledge but we must use reason to intially understand number concepts and scientific deduction/induction to get to the point where we can actually use our senses to then make a complete connection.

The problem with senses in relation to reality also brings up the question of how people with a loss of certain senses make sense of their reality and gain knowledge. If someone is born, let's say, without hearing or taste buds or blind or a combination of any those, sense connection terms become meaningless. What does sweet or bitter or bright or shiny or loud or soft mean to someone who cannot compute such things? Does this mean they go through life unable to make further connections because of their sense deficits? Does this mean that they arent able to gain the same amount of knowledge as someone with all of their senses intact? I am not sure. I would like to say 'of course not!' or 'that's preposterous' but I do not have enough of my own experience of knowledge of this to say those phrases.