According to Kant, morality is the product of the way humans live and not a set of fixed values. Instead of a universal ethic code, Kant suggested a universal procedure that shapes the ethics that differ among groups of people. Humanism is strongly linked to rationality. For humanists, humans are reasonable beings, and reasoning and the scientific method are means of finding truth. Humanists argue science and rationality have driven successful developments in various fields while the invocation of supernatural phenomena fails to coherently explain the world. One form of irrational thinking is adducing. Humanists are skeptical of explanations of natural phenomena or diseases that rely on hidden agencies. Human autonomy is another hallmark of humanist philosophy. For people to be autonomous, their beliefs and actions must be the result of their own reasoning. For humanists, autonomy dignifies each individual; without autonomy, people's humanity is lessened. Humanists also consider human essence to be universal, irrespective of race and social status, diminishing the importance of collective identities and signifying the importance of individuals. Philosopher and humanist advocate Corliss Lamont, in his book The Philosophy of Humanism (1997), states: In the Humanist ethics the chief end of thought and action is to further this-earthly human interests on behalf of the greater glory of people. The watchword of Humanism is happiness for all humanity in this existence as contrasted with salvation for the individual soul in a future existence and the glorification of a supernatural Supreme Being ... It heartily welcomes all life-enhancing and healthy pleasures, from the vigorous enjoyments of youth to the contemplative delights of mellowed age, from the simple gratifications of food and drink, sunshine and sports, to the more complex appreciation of art and literature, friendship and social communion... Themes Morality The humanist attitude toward morality has changed since its beginning. Starting in the 18th century, humanists were oriented toward an objective and universalist stance on ethics. Both Utilitarian philosophy—which aims to increase human happiness and decrease suffering—and Kantian ethics, which states one should act in accordance with maxims one could will to become a universal law, shaped the humanist moral narrative until the early 20th century. Because the concepts of free will and reason are not based on scientific naturalism, their influence on humanists remained in the early 20th century but was reduced by social progressiveness and egalitarianism. As part of social changes in the late 20th century,