The Roman Catholic Erasmus was considered the first Humanist, and all religions lay claim to Humanism as part of their dogma. Atheists know that rationalization of basically false dogmas is futile. If a theological system is logically untenable, it must be abandoned. Ethical Culturism was founded in the late 1800's in America by a Jew, Felix Adler. It was designed to replace religious systems with a system of secular ethics.
Atheists know that ethics and morality have nothing to do with religious systems.
All Atheists have ethics and morals which are gathered from life and human history. Freethinker was the name adopted in early-nineteenth century Europe by those persons who questioned Trinitarian religion and supported the concept of one god. Atheists are not caught up in the game of freedom of interpretation within a theistic system. We are for solutions to human problems here and now, not in some never-never land after death. The concept of a place where all human needs are fulfilled and there is no hunger, poverty, or disease is an attainable goal here and now through human effort and interaction.