Many humanists are compelled to discuss their philosophy of morality because of the common critique that non-religious humans lack a coherent ethical system. For many humanists, questions of right and wrong can be dealt with through the same naturalistic, rational means with which they approach the world in general. Humanism emphasizes the inherent “discoverability” of the universe, arguing that the scientific method provides a sound basis through which one can observe phenomena, make predictions, and test ideas. For many humanists, morality can be approached in this same scientific way. Many humanists advocate a “case by case” approach to ethics, through which one considers the unique conditions of a problem, predicts the various outcomes of any given response to the problem, and chooses to act in accordance with what they believe to provide the best outcome. This method is necessarily experiential and individual. However, many humanists argue that such an approach is a coherent ethical system because it relies on reason and allows for shifting priorities, competing values, and evolving societal standards.
Within humanist communities, several ethical critiques challenge the human-centric nature of the movement. Humanist ecological critiques consider whether placing humans at the center of the ideology and framing human potential as the highest good distorts humanists’ commitment to the environment and other living beings. Some humanists have raised questions humanism’s fundamental goal: does humanism seek to make a world fit for humans, or to make humans fit for the world?
Such ethical questions also involve the humanist consideration of what the “best” of humanity looks like. Although many humanists agree that human consciousness is the result of the functions of the brain and not a separable “soul,” some see natural human limitations as the bounds within which humans should consign themselves to live, learn, and grow. Others see medical and technological advances as opportunities to redefine the boundaries of human potential—extending lifespan, fertility possibilities, physical abilities, euthanasia options, and more. Within these two philosophical camps, there exists an endless range of ideologies to which humanists might ascribe.
Some humanists argue that humanism, as an ideology, is uniquely suited to answer the ethical questions raised by scientific progress, because humanism is an ever-changing approach to human life that relies on subjective reasoning that seeks the best approach to each new question. However, humanists’ responses to ethical quandaries vary based on their philosophy of humanism’s scope and fundamental purpose. Those who see humanism as universal and cooperative often contend that every new scientific advancement should be considered against its potential to uplift or endanger society as a whole. For libertarian humanists, the question of how one might choose to alter one’s consciousness through medical and other scientific developments is often considered a matter of individual choice.