A child is not, as Nietzsche’s Zarathustra calls it, “a first motion”. The “innocence” of the child is in the forgetfulness of the fact that everything, or at least a lot, has been prepared for it. As Jim Morrison says, “We must tie all these desperate impressions together”. The parents are eager to provide the child with ways to do this, with pre-conceived connections, which have proven, for them, to “work” - but “to be workable” is something different altogether from “to be true”. Parents bundle impressions together, or sanction the child’s instinctive bundling-together of certain impressions, by saying: “that is a car”; “that is a plane”. As for the mentioned “instinct”: this “first nature” is actually an inherited second nature, a trait that has been naturally selected in the course of many (many, many) generations, because it “worked” - not because it reflected “the truth”. Certain traits are sanctioned by custom because they have experientially proven to “work”. Thus custom actually legislates natural selection, because those who do what is sanctioned by custom are rewarded with security and privileges - “freedom under the law” -, whereas those that experiment with it, who go “new, untrodden ways”, are “cast out” psychologically or even actually, losing their privileges or even their safety.
Even if I do not entertain any hope of success, I will still try to make you see why I consider your “truth” to be dogmatic.
“A word, once [i.e., in the past] mistaken for knowledge, is really a sound used as a sign for an experience, and it becomes a concept as soon as it is used for more than the one original experience. […] “A concept is an invention to which nothing corresponds entirely, but many things a little,” and so provides a “sign apparatus” for the mastery of great masses of facts. […] The primitive men who formed [language] believed in souls possessing free will as a faculty of capricious action. They projected this notion into things, and came to interpret their own sensations as the “actions” of other “agents,” later as the “qualities” of those “agents.” These superstitions became grammar - subject and predicate, active and passive, etc. Since that time, grammar has been a “folk metaphysic” dominating even the greatest philosophers. […]
Alleged “immediate certainties” […] are really just so many beliefs […]. For instance the Cartesian “I think, therefore I am” involves a number of bold assumptions - that I know what “thinking” and “existence” are, that thinking implies a thinker, that I am the thinker in this case, that the inference indicated by “therefore” is logically valid. Thus it involves judgment, interpretation, and therefore refers to something beyond the “immediate.” […]
Mathematics and logic have also been favorite sources of infallibility. Nietzsche regards mathematics as applied logic, and both as a “sign convention” or “theory of signs” which, in themselves, have no concern with reality at all. As applied to experience, they are animal contrivances of great utility for mastering the environment, but, far from revealing a structure of eternal Being, they positively falsify reality by using such fictitious entities as straight lines, points, and enduring self-identical things. There is no reason, therefore, to take our human logic as more than one of many possible kinds. So in any case neither logic nor mathematics can give certainty about the world.”
[George Morgan, What Nietzsche Means, pp. 248-253.]
I do not wish to imply that you believe in logic (mathematical or linguistic; from the Greek verb legein, meaning “to count” or “to speak”) to the extent described above. I do wish to give you an impression of the extent to which Nietzsche questions assumptions. In principle, every assumption is a questionable one for Nietzsche: hence his “fundamental certainty” which is expressed so well by Harry Neumann (below). As we have to make assumptions, however, in order to function, those ideas that “work” have a value for life (indeed, their value is determined by how well they “work”), but not a truth-value. Apart from the fundamental certainty that there is “something”, which is in a state of flux, there is no truth, but only probability. It is probable that similar, but different experiences from my own exist (i.e., “other people”). I always work with this hypothesis, otherwise how could I function? Your assertion that I exist is not exactly revolutionary for me.