CHAPTER 14: TO KNOW GOD WE MUST USE THE WAY OF REMOTION [CAPUT 14: Quod ad cognitionem Dei oportet uti via remotionis]
[In Scholastic theology, three methods of analogical inquiry were used in discussion of God: the via causalitatis, the via remotionis, and the via eminentiae (or, excellentiae). St. Thomas was treading the via prima (i.e., causality) in the above couple chapters of SCG, where he argued from the effects of the Creator to the existence and nature of the Creator. Since, however, His effects are woefully inadequate to convey God's nature in a fitting way, the other two viae are invoked to balance out the limited gains of the via causalitatis. God is a maker of effects, yes, but He is "remote" from the limitations of makers as we think of them, principally in the way that He creates ex nihilo, whereas lesser makers always have to rely on some medium or tool or model outside themselves. As the IVth Lateran Council stated in 1215, “between the Creator and the creature there cannot be a likeness so great that the unlikeness is not greater [semper maior dissimilitudo in tanta similitudine].” Further, the aspects which we can ascribe to God by analogy with lesser created things (by way of the viae causalitatis et remotionis), we must ascribe to God in an "eminent" or "excellent" way. God is a wise artisan, but eminently and supremely so. God is not simply a rough idea of love, but supereminently love; the Father not simply a paternal pattern, but a supereminently good father, etc.
The methodological "tension" of the viae tritae occurs and re-occurs through SCG and most Scholastic works, so you should keep an eye open for it.]
 We have shown that there exists a first being, whom we call God. We must, accordingly, now investigate the properties of this being.
 Now, in considering the divine substance, we should especially make use of the method of remotion. For, by its immensity, the divine substance surpasses every form that our intellect reaches. Thus we are unable to apprehend it by knowing what it is. Yet we are able to have some knowledge of it by knowing what it is not. Furthermore, we approach nearer to a knowledge of God according as through our intellect we are able to remove more and more things from Him. For we know each thing more perfectly the more fully we see its differences from other things; for each thing has within itself its own being, distinct from all other things. …
 However, in the consideration of the divine substance we cannot take a what as a genus; nor can we derive the distinction of God from things by differences affirmed of God. For this reason, we must derive the distinction of God from other beings by means of negative differences.And just as among affirmative differences one contracts the other, so one negative difference is contracted by another that makes it to differ from many beings. For example, if we say that God is not an accident, we thereby distinguish Him from all accidents. Then, if we add that He is not a body, we shall further distinguish Him from certain substances. And thus, proceeding in order, by such negations God will be distinguished from all that He is not. Finally, there will then be a proper consideration of God’s substance when He will be known as distinct from all things. Yet, this knowledge will not be perfect, since it will not tell us what God is in Himself.
 As a principle of procedure in knowing God by way of remotion, therefore, let us adopt the proposition which, from what we have said, is now manifest, namely, that God is absolutely unmoved. The authority of Sacred Scripture also confirms this. For it is written: “I am the Lord and I change not” (Mal. 3:6); ...“with whom there is no change” (James 2:17). Again: “God is not man... that He should be changed (Num. 23:19).