Where did Swedenborg believe man originate from?

Although Emanuel Swedenborg (1688–1772) had a distinguished career as a scientist during his younger and middle years of adulthood, in his mid-fifties he ceased his scientific work and turned to spiritual subjects instead. His theological works, published between 1749 and 1771, in the later period of his life, are devoted almost entirely to Bible interpretation, theology, and accounts of his experiences in the spiritual world. His occasional references to scientific ideas function mostly as illustrations of the spiritual concepts he is presenting.

And in general, the science in his theological works is no more advanced than the best science of his day, together with some of his own speculations on scientific subjects.

In the 18th century when Swedenborg wrote and published his theological works:

• Darwin had not yet proposed the theory of evolution of species.
• Modern pseudoscientific theories of alien origins of humans on earth did not yet exist.
• The Creation stories of Genesis were still the dominant source of belief about human origins.

Swedenborg, then, did not have access to contemporary evolution and alien origin theories for how humans came to be.

And during his theological period Swedenborg rejected traditional literal interpretations of the early chapters of Genesis, stating instead that the Creation stories of Genesis were written in a purely symbolic style. Specifically relevant to the current question, he said that there were no individual human beings named Adam and Eve, but that those early figures in the Bible are symbolic of whole early communities human beings.

As to how humans did originate physically, Swedenborg said very little. In fact, there is only one passing reference in his theological writings to how the various species on earth originated. It comes in a conversation that Swedenborg reported having with an angel:

God is absolute love and absolute wisdom. His love includes an infinite number of feelings. His wisdom includes an infinite number of perceptions. The correspondences of those feelings and perceptions are all the things that appear on earth. This is where the birds and animals come from. This is where the trees and shrubs come from. This is where the grains and crops come from. This is where the plants and grasses come from. . . . The difference is that in our world God creates things of this kind in a moment to match the feelings of angels, while in your world things like this were originally created in a similar way but there was a provision for their perennial renewal from generation to generation; and so creation goes on. (True Christianity #78:3)

In other words, the angel is saying, in the material world God originally created the species instantaneously as an expression of some corresponding element of the nature of God or of some element of the inhabitants of the spiritual world, but that on earth God gave the species the ability to reproduce themselves from then onward.

This is in accord with a common theory of the day with regard to how animals came into existence: spontaneous generation. Earlier in his theological works, in Divine Love and Wisdom #340–344, Swedenborg supported the theory of spontaneous generation in a discussion of where maggots and noxious insects come from.

Apparently, then, Swedenborg believed that originally God created each species directly, giving it the ability to reproduce itself and continue its species by that means, and that in some cases spiritual influences could still directly create smaller living creatures as an expression of particular good or evil thoughts and desires.

Spontaneous generation has since been thoroughly disproved through numerous scientific experiments. And the theory of evolution has long since displaced from scientific thought the idea that humans were originally created instantaneously by God. This has caused cognitive dissonance for some Swedenborgians who are loath to accept that Swedenborg could have been mistaken on these subjects. However, most Swedenborgians today believe that Swedenborg's statements on scientific subjects come more from Swedenborg's own mind and knowledge than from any divine inspiration. Most Swedenborgians today are content to accept the conclusions of science about evolution and other natural phenomena.

As for the fact that it was an angel who stated that God created the species on earth instantaneously, this is likely due to the fact (in Swedenborg's theology) that angels do not think materially, but spiritually, and therefore do not have any special insight into matters of natural science. Angels are apparently dependent upon humans arriving in the spiritual world from earth for any scientific information or theories they may have about the workings of the physical universe.

In short, the angel in this conversation was probably just reflecting a theory about the origins of humans and other species that was current on earth at a time before Darwin had proposed the theory of evolution.

TL;DR: Swedenborg apparently believed that humans were originally created directly by God, and given the ability to reproduce themselves from there. However, most Swedenborgians today accept the theory of evolution as the means by which the human species physically originated on this earth.