Some who nonetheless would like to use government to promote their religion have argued that the First Amendment works only in one direction–to protect religion from government, but not the other way around. This, they suppose, would leave them free to insinuate their religion into government and thereby effectively establish it as the nation’s religion. To the extent that the First Amendment prevents that, it can be said to at least have the effect of protecting government from religion. Indeed, the notion of a one directional wall is self-contradictory: If any church is free to so influence and control government and thereby achieve a favored or established status, all individuals are at risk of their religions falling into disfavor with government and facing discriminatory treatment. One of the primary aims of the First Amendment is to prevent just that.

Separation of church and state does not prevent citizens from making decisions and voicing opinions based on principles derived from their religions. Moreover, the religious beliefs of government officials naturally may inform their decisions on policies. In this context, the principle of separation of church and state does, though, constrain government officials not to make decisions with the predominant purpose or primary effect of advancing religion; in other words, the predominant purpose and primary effect must be nonreligious or secular in nature. A decision coinciding with religious views is not invalid for that reason as long as it has a secular purpose and effect.

Confusion understandably arises because the constitutional principle is sometimes equated with a widely supported political doctrine that generally calls for political dialogue to be conducted on grounds other than religion. The underlying reasons for that approach are many, but two primary ones are that it facilitates discussion amongst people of all beliefs by predicating discussion on grounds accessible to all and, further, it avoids, in some measure at least, putting our respective religious beliefs directly “in play” in the political arena, so we’re not put in the position of directly disputing or criticizing each other’s religious beliefs in order to address a political issue. This political doctrine, of course, is not “law” (unlike the constitutional separation of church and state, which is), but rather is a societal norm concerning how we can best conduct political dialogue in a religiously diverse society. Reasonable people can disagree about whether the doctrine is a good idea or not and whether or how it should influence us in particular circumstances.

TJ lived during the time Great Britain, Ireland and the British colonies eventually converted to the Gregorian calendar, so he instructed that his tombstone bear his dates of birth and death in the Old Style and New Style, respectively.
At Jefferson’s birth the difference would have been eleven days between styles, had the New Style been converted to yet, as is evidenced by his “original” birthday of 2 April and his New Style birthday of 13 April.