We must impute equal merit to the early thinkers who showed the way and to the later thinkers who pursued it.

If the ancient attempts to explain the universe have been recently replaced by the discovery of a simple system (the Cartesian), we must consider that the truth could only be reached by the elimination of false routes, and in this way the numbers of the Pythagoreans, the ideas of Plato, the qualities of Aristotle, all served indirectly to advance knowledge.

"We are under an obligation to the ancients for having exhausted almost all the false theories that could be formed." Enlightened both by their true views and by their errors, it is not surprising that we should surpass them.
But all this applies only to scientific studies, like mathematics, physics, and medicine, which depend partly on correct reasoning and partly on experience.

Methods of reasoning improve slowly, and the most important advance which has been made in the present age is the method inaugurated by Descartes.

Before him reasoning was loose; he introduced a more rigid and precise standard, and its influence is not only manifest in our best works on physics and philosophy, but is even discernible in books on ethics and religion.
We must expect posterity to excel us as we excel the Ancients, through improvement of method, which is a science in itself--the most difficult and least studied of all--and through increase of experience.