The earliest formal accounts of the soul probably came from ancient Egypt and Babylonia but I want to begin with ancient Greece since there is a clear link to later monotheistic religions.
Not only have that but Hindu philosophy has strong links to Greek Aristotelian metaphysics as they share a fundamental common theme embracing a divine and immortal mind or soul.
Aristotle’s metaphysics is analogous to the ideas of the Upanishads which locates the inner self, whose spirituality was of great interest to Albert Schweitzer.
For in Greek thinking both Plato and Aristotle believed in immortality but there was a distinction in relation to the soul. Plato's idea was of a soul as indestructible part of the body versus Aristotle’s view it was the intellect and not the soul that survives death.
Greek thinking influenced monotheism for thousands of years with Aristotle’s metaphysics integral to both the Christian, Muslim and Jewish religions. For instance, Aristotle ideas were incorporated into Islamic thinking, when his significant first ever formal works on metaphysics were translated into Latin. Islamic scholars were much more open then to new ideas before later retreating into more of fundamental stance. Christianity similarity adopted his ideas that were incorporated into the great religious philosopher of the 13ty Century, Thomas Aquinas.
His religious philosophy was officially endorsed by the Roman Catholic Church in 1907.
A similar position arose with the Jewish philosopher Moses Maimonides, who eventually asserted the resurrection of the dead is a fundamental principle of Judaism
The formulation of dogma was helpful to Jews pressured to defend their religion and needing to have ready replies to theological attacks on it. Maimonides formulated the last of which is belief that the dead will be brought back to life when God wills it.
By the 13th century that view became accepted into Judaism, and as Maimonides included it among his .
But it should be noted in the early periods there existed much more diversity than there is now in the Christian religion.
By way of example it wasn’t until the 6th century that the idea of reincarnation was considered heretical.
This isn’t surprising given the eschatological expectations of a messiah that permeated Jewish thinking just prior to the unexpected execution of Christ.
That idea of messianic figure was rife at the time whose expectation was for the Jews to gain their freedom from the Roman yoke as was foretold in the latter OT texts and in particular to the book of Daniel.
According to Professor Hubert Dreyfus and Sean Kelly in their publication “All Things Shining”, what began in Christianity under the influence of Pauline influences to combine Jewish mysticism with Greek rationality was a bad idea.
For the Greeks of Plato’s era, in the 5th century BC, human’s beings had one, single universal essence: at their best they were rational agents who, through disinterested philosophical argument, could discover objective, universal, timeless truths of nature and human ethical excellence. For the Hebrew it was the special covenant with GOD. The truth then was commitment to the covenant. To some degree this conflict of cultural ideas continued except for those devotees of Kierkegaard, who accepted his synthesis.
In terms of the so-called eastern religions composed principally of Hinduism, Buddhism, Taoism and Confucianism, Buddhism took its lead from Hinduism less the priestly connections with worship and associated rituals. It was to spread across SE Asia to be further morphed into different strands along the Silk Road as it incorporated aspects of Taoism in China. There is some debate as to whether Buddhism is a religion or a philosophy. Based on the idea that religion is defined as the worship of a God (rather than the rejection of worship) in that sense Buddhists is a philosophy.
But if you define religion as a belief which promises reality and involves the study of sacred texts I think it can be regarded as a religion. There are many different strands as for instance Tibetan Buddhism incorporated the idea of local Gods into its basic tenet.
The differences between Hinduism and Buddhism also relates to the idea of the negation of the self. In Hinduism, human soul, is believed to be connected to the Brahman. However, Buddhism in its enlightened state negates the idea of a self, believing its independence cannot be separated. However, what might be construed on the pathway to enlightenment is a duality. Therein we have the conventional sense of self that applies only until such a state of enlightenment is realized.
First Nations People
Interestingly the Australian Aboriginal society, existing for possibly some 70,000 years in isolation pre colonisation held similar views to all of the world’s major religions and in particular in relation to the soul.
They believed that the dreaming one is reincarnated to return in different existential forms to inhabit the land to which they are inextricably joined. So they believed the land owned them and so the idea of owning land was nonsense. Life was a continuous circle defined by predestined totems and the law which gave rise to kinship and the means of governance without the need for supreme rulers.
Finally we can turn to our modern way of viewing the immortal soul which depends in turn on how we view the mind and consciousness. In respect of our mind dependent consciousness and what is deemed reality is a source of continuous debate.
On the one hand we have the hard- nosed materialists who believe that the output of the brain and our consciousness can only be the product of the human brain. That view contrasts to the non- materialists who argue consciousness is a fundamental state in the universe to which we are all inexplicably linked.
Such questions will remain debating issues since no one can be absolutely sure what reality is.
So that ultimately it boils down into what you believe and that’s where the ABC‘s recent research as in the Conversation talking about a survey into the soul in 2021 is of interest. The results suggest that, as a nation, we may not be as sceptical as we think we are.
The survey results showed that on an overall basis 69.7 percent of respondents said they either believed in or were open to the existence of the soul, with 14.7 percent unsure, 5.7 percent thinking it unlikely, and 9.9 percent saying they do not believe it exists.
But only 48 per cent of Australians say they believe in ghosts or the possibility they may exist, but 69 per cent say the same for the soul, according to new research.
What about young people
Surprisingly, perhaps, it was the youngest age group — 18-26-year-olds — who expressed the most openness to the non-material: 49 per cent said they believe in the soul, and 48 per cent in life after death (in both cases, another 28 per cent were open to the possibility).
The percentage who said "I believe this does not exist" about any of the options never rose to double digits for this cohort (9 per cent for ghosts, only 4 per cent for life after death).
By contrast, the oldest age bracket (76+) were much more sceptical: a full 40 per cent said they do not believe in ghosts, and 28 per cent dismissed the possibility of life after death.
The gender disparities will be less surprising to some. Men were on average more than twice as likely as women to tick the "I believe this does not exist" box.
When it comes to the existence of God or a higher power, men and women said they believed or were open to it at almost the same rate. But for the rest, women were markedly more willing to profess belief: 50 per cent to 38 per cent for the soul, 38 per cent to 30 per cent for life after death, 34 per cent to 26 per cent for angels.
Soul-searching summing up.
So that we can conclude the question of souls is still one that matters. It is, in effect, wrestling with the meaning of human life and what is it that makes us human — and whether each of us is more significant than the rocks or pebbles in the sea.
In my view it’s not so much the doctrines of the various religions that bind its followers, for there will be matters of interpretation, but rather that search for meaning that continues so that the division between the secular and sacred is rather blurred. Like adherents of Buddhism emphazising it’s a philosophy and not a religion by pointing out the tenets of their sacred texts and beliefs in the path to enlightenment. But mostly something that is considered sacred is connected to religion and if you change a definition of region not to mandate worship of a GOD but reality with sacred texts than it is a religion.
So, Buddhism is a religion like any others which all have their philosophical underpinnings. Then there is far more commonality in religious thinking than we might think except for a few twists along its evolutionary journey. Talking to people who have converted from Christianity to Buddhism they believe Christ was a reincarnated Buddha. People will continue to adapt as will our beliefs, slowly over time.
This is why the belief in souls persists, even in this apparently secular age.