has the restoration of the arts and sciences improved our morals?

Rousseau thinks nope.

He writes,

In fact, whether we turn to the annals of the world, or eke out with philosophical investigations the uncertain chronicles of history, we shall not find for human knowledge an origin answering to the idea we are pleased to entertain of it at present. Astronomy was born of superstition, eloquence of ambition, hatred, falsehood and flattery; geometry of avarice; physics of an idle curiosity; and even moral philosophy of human pride. Thus the arts and sciences owe their birth to our vices; we should be less doubtful of their advantages, if they had sprung from our virtues.

He argues

 Their evil origin is, indeed, but too plainly reproduced in their objects. What would become of the arts, were they not cherished by luxury? If men were not unjust, of what use were jurisprudence? What would become of history, if there were no tyrants, wars, or conspiracies? In a word, who would pass his life in barren speculations, if everybody, attentive only to the obligations of humanity and the necessities of nature, spent his whole life in serving his country, obliging his friends, and relieving the unhappy? Are we then made to live and die on the brink of that well at the bottom of which Truth lies hid? This reflection alone is, in my opinion, enough to discourage at first setting out every man who seriously endeavours to instruct himself by the study of philosophy.

In what can be described as a critique of philosophy, he asks

What is philosophy? What is contained in the writings of the most celebrated philosophers? What are the lessons of these friends of wisdom. To hear them, should we not take them for so many mountebanks, exhibiting themselves in public, and crying out, Here, Here, come to me, I am the only true doctor? One of them teaches that there is no such thing as matter, but that everything exists only in representation. Another declares that there is no other substance than matter, and no other God than the world itself. A third tells you that there are no such things as virtue and vice, and that moral good and evil are chimeras; while a fourth informs you that men are only beasts of prey, and may conscientiously devour one another. Why, my great philosophers, do you not reserve these wise and profitable lessons for your friends and children? You would soon reap the benefit of them, nor should we be under any apprehension of our own becoming your disciples.

Source go read it.