There is a sense in which I would agree with this premise, but suspect it is not the same as yours. I would be very interested in what it is on which you base this concept. I do not believe in "a priori" knowledge of any kind, so, if that is your premise, please be prepared to defend it. (Not that you have to answer to me for anything, I mean only for the sake of discussion, I hope you understand.)
Hank
Well it's obvious to me that some "a priori" knowledge exists in the form of instinct. Instinctual knowledge can be readily observed with lower animals.
Man may demonstrate less instinctual knowledge as well as ability than many other animals at birth. But he is a more complex creature, requiring more time to develop.
As far as knowledge of right and wrong, I suppose that the biggest factor making me believe in an innate conscience as opposed to taught values is scripture. Romans 2 (at end of post) clearly states this is the case.
Which of course raises the question, "Why do I believe in scripture?". For the moment, I will simply say that it is a combination of personal experience, logic, the purity of the goal of human conduct that scriptures promotes, and it's ability to change human behavior. I will try to give a more detailed explanation for that belief later.
And it's actually going to get more complicated than that as I believe the conscience is not only internal innate knowledge but at times includes external subconscious communications with God and angels. Such belief also being based in part on scripture.
While I believe that man is born with a knowledge of right and wrong, he is also born with a fallen nature which makes him somewhat rebellious. Thus all men will eventually test the boundaries and do what they know to be wrong.
The rebellious nature is inherited, but the decision to do wrong invariably deals with man's desires. The Garden of Eden being a good example, Eve ate of the fruit of the tree of knowledge of good and evil because she saw that the fruit was 1) good for food, 2) a delight to the eyes, 3) and would make her wise (more like God by having knowledge of good and evil).
Eve also had a desire to obey God and to not die. The former was overridden by the focus that she had on the benefits of the fruit as well as the serpent planting distrust of God. The latter was overridden by accepting the Serpent's lie that Eve would not die and again the distrust of God.
Had Eve been a logic expert she would have realized that having already corrected the Serpent once, the serpent's information was more likely to be faulty than's God's. But she didn't, and here we are. The moral of the story being "who do you trust?" and "given conflicting information who do you obey?"
All acts of man, whether good or evil are driven thus by man's desires. The values and beliefs that we hold are a subset of those desires. The study of philosophy and values develops a construct where one can rank order or otherwise develop a greater knowledge of those desires and develop value rules or morals. That study and reflection of one's desires allow the desires themselves to change.
Romans2:14 When Gentiles who have not the law do by nature what the law requires, they are a law to themselves, even though they do not have the law. 15 They show that what the law requires is written on their hearts, while their conscience also bears witness and their conflicting thoughts accuse or perhaps excuse them 16 on that day when, according to my gospel, God judges the secrets of men by Christ Jesus. Which of course is going to raise the question of why I believe in scripture.