Rationality without empiricism is impossible. A child born without experience is not considered “alive” for a reason. (This may sound circular but) we necessarily start with reality, then experience, then thought (reason). What ends in death is experience and thought but not reality, for the body remains.
This may be a common sense view, a conventional view, a “reductive” point-of-view but there is nothing that I should apologise for … except for being boring perhaps.
It is not
I think therefore I am,
I think I am, therefore I am.
The difference is one of illusion.
Inductive reasoning is reasoning in which the premises are viewed as supplying strong evidence for the truth of the conclusion. While the conclusion of a deductive argument is certain, the truth of the conclusion of an inductive argument is probable, based upon the evidence given.
From Essentials of Logic by Copi, Cohen and Flage.
I do not think we can ever come to a certain truth, because we have only access to the reality through our senses and perception. It must forever be probable. So philosophy will always be an argument of who has got the better probability.
The dispute between rationalism and empiricism concerns the extent to which we are dependent upon sense experience in our effort to gain knowledge. Rationalists claim that there are significant ways in which our concepts and knowledge are gained independently of sense experience. Empiricists claim that sense experience is the ultimate source of all our concepts and knowledge.
From Stanford Encyclopaedia of Philosophy.
I agree with Rationalists that concepts and knowledge can be gained independently of sense experience, insofar as there is nothing outside of space-object-time. Some kind of knowledge must exist first of space-object-time before other kinds of concepts and knowledge can come into being independently.
Empiricist are therefore right to claim also that sense experience is the source of all our concepts and knowledge, insofar as rational concepts and knowledge depends on the first source of sense experience.
There are therefore two sources of knowledge – sense experience and reasoning. Rationality must come from the first instance of sense experience, be it a lifetime of one second or one hundred years. Without that “spark” there are no rational concepts and knowledge.