Individualism

These medieval tendencies came to fruition during the sixteenth and seventeenth centuries, so that individualism in the modern world deserves to be understood as a culmination of far earlier intellectual trends. The Reformation brought not only a challenge in practice to the unity of the Christian Church but also a transformation of important theological categories. Martin Luther (1483–1546) insisted on the unique presence of God alone in the conscience of believers, with the implication that the faithful Christian is responsible directly and immediately to God. The consequence of this teaching—while perhaps recognized only fleetingly by Luther and his followers—was that salvation did not depend on submission to the authority of the priesthood or the church. Nor did it fall to the secular power, to which pertained the control of bodies and behavior, to discipline the souls of subjects. Thus, whether intentionally or not, Luther opened the door to claims of public respect for liberty of conscience and eventually individual freedom of worship.

In the generation after Luther, inferences about personal freedom of religion were deduced by reforming thinkers. Sebastian Castellion (1515–1563) published pseudonymously a treatise entitled De haereticis, an sint persequendi (On heretics, whether they are to be persecuted) in response to John Calvin's organization of the burning of a fellow Christian theologian for heresy at Geneva. Castellion argued that Christian belief must be held with sincere conviction. Hence, clerics and magistrates must refrain from persecution of convinced Christians who cling to doctrines that do not coincide with official teachings. Castellion maintained that the individual Christian's duties extend to forbearance of the free and honest faith of one's fellows even in the face of disagreements of understanding and interpretation.

In the seventeenth century, the individualism implicit in confessional pluralism would become more pronounced. For instance, Baruch Spinoza (1632–1677) claimed a broad application for the right to liberty of thought and belief without interference from a sovereign power's (or a church's) determination of the truth or falsity of one's ideas. Pierre Bayle (1647–1706) asserted that all forms of persecution (innocuous as well as harsh) of religious diversity encourage hypocrisy and erode social order. An erring conscience, if it be held in good faith, deserves as much protection as a correct one—a principle that Bayle extended even to atheists.

John Locke (1632–1704) proposed liberty of individual conscience as justified in the case of most Christian (and perhaps some non-Christian) rites. For Locke, the role of the magistrate should be confined to the maintenance of public tranquility and the defense of individual rights rather than the care of the soul. Hence, Locke's Letter concerning Toleration (1690) defended a vision of the church as a purely voluntary association that a believer was free, according to conscience, to enter or leave at will. Locke crystallized a key Reformation shift: the idea that one's religious confession is a matter of individual choice rather than institutional imposition.

The evolving acceptance of individualism paralleled changes in other European cultural, social, and political practices and attitudes. The invention of the printing press and movable type in the mid-fifteenth century immeasurably enhanced the ability of individuals to spread their ideas and made it possible for a larger public to access the written word. Demands were heard for freedom of the press (literally and figuratively) from censorship by clerical and secular authorities alike. While republican values that promoted civic virtue over personal choice retained a hold on public discourse, political liberty in geographically extensive regimes with monarchic institutions tended to be conceived in terms of individual freedom rather than civic populism. Hence, it is at this time and place that the origins of the bundle of individualist doctrines known as liberalism are found.