Swedenborg, Emanuel - The seed of all natural things
Type of Spiritual Experience
This can be read any number of ways.
Swedenborg was trying to descibe the ultimate cause of creation - the building block on which everything else is based, as such he my have meant the atom or he may have meant the unit of energy. Given that he is describing form and not function, it is more likely he is describing the 'atom'.
A description of the experience
Emmanuel Swedenborg –The Infinite and the final cause of creation
It is the seed of all natural things; that it is their principle, that it is that out of which, by degrees and moments, ultimate nature is unfolded; in a word, that there is in it, a primitive entity, everything whatever that we can possibly conceive as existing in nature, and that this is this prime; and in an indefinite number
For nothing can be produced from a seed unless the seed contain an aptitude for, and a quality of, producing it, or developing itself. And though this quality may seem to exist in the sequences or derivatives as well, yet still they must have received their share of it from their first principle; showing therefore that in the latter lay cause and quality and the whole scope and power of the primitive.