As the writings of which I speak, together with other influences, have served to produce phases of religious thought amongst ourselves, so amongst them, the writings of earlier theologians, together with other influences, served to produce the characteristic peculiarities of their religious thought. We are apt to underrate the _number_ of ways in which thinking is affected; and we often forget that a simple result may proceed from most complex and composite causes. Many people imagine that the climate of a country is determined entirely by position in point of latitude--that every mile nearer the pole it must be colder, and every mile nearer the equator it must be warmer; whereas numerous and diversified agencies interfere with climate, and produce wonderful curves in the isothermal lines. So, many people imagine that one cause--the study of the Bible--solely determines theological opinion; whereas, forces of all descriptions--even climate and scenery, race and language, laws and memories, especially early education, domestic life, books, friendships, and idiosyncrasies--have a share in the result. Divines two centuries ago might not, any more than ourselves, be conscious of the diversified and subtle operations to which they were subjected; but that circumstance does not interfere with the fact itself. [Sidenote: THEOLOGY.] There had been four broad lines of theological opinion long before the middle of the seventeenth century, as there have been four broad lines running on ever since. In the second century and onward we meet with _patristic orthodoxy_, the great facts and principles of Christianity taught by the Apostles being illustrated and defended, especially in the Nicene age, by thoughtful men, who, in the use of their natural faculties, by the blessing of Almighty God, explained and established much which is true; not, however, without an admixture of something which was false. In the third century we meet with _Alexandrian philosophy_, which, by a natural tendency, aimed at bringing the intellectual culture of the age into connection with the Gospel; and therefore dwelt much upon the reasonableness of Christianity, and the points of affinity between it and certain forms of human opinion. In the fourth century we find _dogmatic Evangelicalism_ gathered up by Augustine, and woven into a distinctive system of Christian thought. At the same time the element of _Mysticism_ appears at work, preparing for a vigorous expression of itself during the middle ages. Throughout those ages these four currents are traceable, generic resemblances, being marked, of course, by specific varieties. At the Reformation two of these, the Nicene and the Augustinian, are manifest enough in the English Protestant Church, both struggling against Rome; each also struggling with the other. The traces of Alexandrianism and of Mysticism, after disappearing for awhile, become distinctly visible in the seventeenth century.