Some time ago, I read Hobbes's Leviathan, a classic argument for the existence of a social contract. I recently became aware of the existence of Spinoza's Treatise, which argues for freedom of thought, speech, and religion. I was surprised to discover a common theme in these early modern works of political philosophy, which I did not expect. I knew from second-hand literature that both contain rational arguments about what powers secular authorities should and should not be recognized to possess.
But I was surprised to find both philosophers engaged in interpreting the bible. Both Hobbes and Spinoza quote passages warning about false prophets. Spinoza gives naturalistic principles of reading. For example, he thinks philosophical doctrines in the bible should be read with the understanding that the authors were writing to engage the understanding of the common people of the day. I did not expect that Spinoza would cite the Israelites under Moses as the canonical example of a social contract. Spinoza, kicked out of their community by the Amsterdam Jews, writes quite a bit about the New Testament. I guess this excommunication may have had something to do with more than his identification of God with the cosmos, the Creator with the creation. (I tried to read the Ethics, with its geometric proofs, long ago.)
Hobbes and Spinoza have another commonality. They spend quite a bit of time cataloging, explaining, and analyzing human sensations, emotions, and qualities. I resist the idea that certain perspectives on human nature map directly to political positions. Mayhaps, this sort of analysis of the human psyche was part of a naturalizing Enlightenment project.
I suppose addressing the topic of religion makes sense in these books. The political authorities of the day were often claiming to rule in the name of God, I gather. I do not know much about, for example, the Spanish Inquisition, but, from what I understand, the Jewish community in Amsterdam contained many families that had fled Spain. The political situation in England often saw an entanglement of religion and politics, what with the beheading of Charles I, the rule of the puritan Oliver Cromwell, the English Revolution, and so on. So if you are going to write on politics, you might want to explain how the reader need not accept the unargued proclamations of supposed authorities. You might want to explain, also, how your ideas are consistent with religion, rightly understood.
As far as I know, many later writers arguing for liberalism in thought and speech did not feel the need to argue about what secular authority can and cannot be deduced from the Bible. As examples, I do not recall any such themes in either Rousseau or Mill.
Caveat: writers on general philosophy will include matters of epistemology and ethics. How can we come to know what ethical principles to follow, if we can? I gather that Hume is an example of such an argument. I do not know if his characters take authority from Bible verses.References
- Thomas Hobbes (1651). Leviathan Or The Matter, Forme, & Power Of A Common-Wealth Ecclesiastical and Civill.
- David Hume (1779). Dialogues Concerning Natural Religion [TO READ].
- John Locke (1689). A Letter Concerning Toleration. [TO READ].
- John Stuart Mill (1859). On Liberty.
- Jean Jacques Rousseau (1755). A Discourse on the Origin of Inequality.
- Jean Jacques Rousseau (1762). The Social Contract.
- Benedict de Spinoza (16669-1670). Theological-Political Treatise.