In these works, she attacked also the fad of free-thinking in vogue among the young men of the time.  She was one of the few women of that age who could not separate themselves from reason and thought, even in religion; the latter was a matter for the reason and the intellect to decide, and was thus an elevated product of the mind rather than an instinct coming from the heart, or a positive revelation as it was in the seventeenth century.  In this view, Madame de Lambert indicated the beginning of the later eighteenth-century spirit.

Mme. de Lambert taught her children to be satisfied with nothing but the highest attainable object.  She advised her son to choose his friends from among men above him, in order to accustom himself to respectful and polite demeanor; “with his equals he might cultivate negligence and his mind might become dull.”  She desired her children to think differently from the people—­“Those who think lowly and commonly, and the court is filled with such.”  To their servants they were to be good and kind, for humanity and Christianity make all equal.  She was the first to use those words, “humanity” and “equality,” which later became the bywords of everyone, and the first to teach that conscience is the best guide.  “Conscience is defined as that interior sentiment of a delicate honor which assures you that you have nothing with which to reproach yourself.”

Possibly the most important and lasting effect of Mme. de Lambert’s influence resulted from the expression of her ideas on the education of young women who “are destined to please, and are given lessons only in methods of delighting and pleasing.”  She was convinced that in order to resist temptation and be normal, women must be educated, must learn to think.  Her counsels to her daughter are remarkable for an unusual insight into the temperament of her sex and for an extreme fear that makes her call to her aid all precautions and resources.  She thus advises her daughter: 

“Try to find resources within yourself—­this is a revenue of certain pleasures.  Do not believe that your only virtue is modesty; there are many women who know no other virtue, and who imagine that it relieves them of all duties toward society; they believe they are right in lacking all others and think themselves privileged to be proud and slanderous with impunity.  You must have a gentle modesty; a good woman may have the advantages of a man’s friendship without abandoning honesty and faithfulness to her duties.  Nothing is so difficult as to please without the use of what seems like coquettishness.  It is more often by their defects than by their good qualities that women please men; men seek to profit by the weaknesses of good and kind women, for whose virtues they care nothing, and they prefer to be amused by persons not very estimable than to be forced merely to admire virtuous persons.”

This is a most faithful description of the society of her time, and it was because her treatises struck home that they were severely criticised; but, nothing daunted, she carried out her plans in her own way, resorting neither to intrigue nor artifice.  Many of her sayings became household maxims, such as—­“It is not always faults that undo us; it is the manner of conducting ourselves after having committed them.”