In the first installment of this series I left the reader with a few questions that Johann Heinrich Alsted proposes to himself in anticipation of his readers’ objections to his proposal of natural theology as a discipline. The first question has to do with the similarities and differences between natural theology and natural philosophy, or what we popularly call “science” today.
To the first question: Some may say that natural theology brings about an excessively wordy dialogue (perissologiam). If natural philosophy already covers these topics, why add another science for investigating nature?
[N]ulla est hic perissologia. Illa enim est rerum supervacuarum expositio. At non sunt supervacaneæ res illæ, quæ hic ex physica repetuntur. Nam res considerata potest esse communis multis disciplinis: at modus considerandi, illam communitatem restringit, non secus ac forma determinat materiam. Iam vero res illæ in Physicis considerantur sub hac formalitate, quatenus sunt corpora naturalia; in Theologia naturali sub ista, quatenus sunt muti præcones gloriæ divinæ. Ais: At tu considerasti etiam hic illarum rerum naturam. Aio: Hoc fuit omnino necessarium, ut breviter & populariter illud proponerem, quod prolixe & accurate in Physiologia exponitur. Movit me etiam hæc causa, quod plerique studiosi Theologiæ vel non degustant Philosophiam naturalem, vel authores non habent, qui plane illam persequuntur, vel indignantur, si videant librum naturæ non plane discriptum & expositum esse. Atque, ita lex prudentiæ stat quoque a meis partibus. Summa hæc est: Quicunque vult aperire & evoluere librum natura, naturam quoque cognoscere debet. Physicus naturam cognoscit quatenus est natura & ministra Dei; Theologus naturalis, quatenus est magistri hominis, (Theologia naturalis, Preface, 12-13).
[T]here is no perissologia here. For a perissologia is an exposition of superfluous things. But these things, which are repeated from natural philosophy, are not superfluous. For the object of examination may be common to many disciplines, but the mode in which the object is examined limits its commonality, non unlike the way that form determines matter. Besides, these things are examined in natural philosophy under this form, insofar as they are natural bodies; in natural theology [they are examined under a different form] insofar as they are the silent heralds of divine glory. You respond: “But you are also examining here the nature of these things.” I reply: “This was completely necessary in order that I might propose briefly and in common language that which is put forth at length and with accuracy in books of natural philosophy.” I am also motivated by the following reason, that very many who are devoted to theology either do not have a taste for natural philosophy, or do not consider the authors [of that science] who will be openly hostile or heap scorn upon them if they should see the book of nature described and explained incompletely. And so the law of prudence is also established on my part. In sum: Whoever wants to open and unfold the book of nature should also become acquainted with nature. The natural philosopher is acquainted with nature insofar as it is nature and God’s handmaid; the theologian of nature [is acquainted with nature] insofar as [nature] is man’s instructor.