Letter XVIII. ( a.d. 390.) To Cœlestinus Augustin Sends Greeting. 1. Oh how I wish that I could continually say one thing to you! It is this: Let us shake off the burden of unprofitable cares, and bear only those which are useful. For I do not know whether anything like complete exemption from care is to be hoped for in this world. I wrote to you, but have received no reply. I sent you as many of my books against the Manichæans as I could send in a finished and revised condition, and as yet nothing has been communicated to me as to the impression they have made on your 1478 judgment and feelings. It is now a fitting opportunity for me to ask them back, and for you to return them. I beg you therefore not to lose time in sending them, along with a letter from yourself, by which I eagerly long to know what you are doing with them, or with what further help you think that you require still to be furnished in order to assail that error with success. 2. As I know you well, I ask you to accept and ponder the following brief sentences on a great theme. There is a nature which is susceptible of change with respect to both place and time, namely, the corporeal. There is another nature which is in no way susceptible of change with respect to place, but only with respect to time, namely, the spiritual. And there is a third Nature which can be changed neither in respect to place nor in respect to time: that is, God. Those natures of which I have said that they are mutable in some respect are called creatures; the Nature which is immutable is called Creator. Seeing, however, that we affirm the existence of anything only in so far as it continues and is one (in consequence of which, unity is the condition essential to beauty in every form), you cannot fail to distinguish, in this classification of natures, which exists in the highest possible manner; and which occupies the lowest place, yet is within the range of existence; and which occupies the middle place, greater than the lowest, but coming short of the highest. That highest is essential blessedness; the lowest, that which cannot be either blessed or wretched; and the intermediate nature lives in wretchedness when it stoops towards that which is lowest, and in blessedness when it turns towards that which is highest. He who believes in Christ does not sink his affections in that which is lowest, is not proudly self-sufficient in that which is intermediate, and thus he is qualified for union and fellowship with that which is highest; and this is the sum of the active life to which we are commanded, admonished, and by holy zeal impelled to aspire. 1478     The sense here obviously requires “ vestri ” instead of “ nostri, ” which is in the text.