I'm not sure I would agree.
To my mind, our capacity for
empathy and identification with others has been the key driver of human moral progress throughout history, and this was obviously derived both from our own sense of self (and recognising that other people were also 'selves' just like us with similar feelings, wants, needs and desires) and our sociability as tribal beings, reared in families and friendship groups for survival purposes.
There are many studies demonstrating that people often make moral judgements intuitively, with reason having an important but ancillary role.
Reason by itself, as abstract logic, can result in very diverse justifications for practices that many of us in the West would regard as grossly immoral but not necessarily
irrational or devoid of logic. Reason
with empathy has certainly been essential to arguments about morality and changing moral norms, but by itself - no, I don't think so.
I would take '
eugenics' as an example (both negative - i.e. 'left to die' - and positive, that is actively killing)
Amongst many ancient Greeks and Romans, it was deemed perfectly in keeping with reason for those of a weak, hereditary constitution or with a disability or mental illness to be left to die, without receiving care from the rest of society at society's expense and also to be prohibited from breeding. Thus, infanticide by exposure was endemic in these societies and the founding constitution of the Roman Republic - the
Twelve Tablets - actually mandated, as stated in Cicero’s dialogue
De Legibus (Cic. Leg.iii 8.19): "
cito necatus tamquam ex tabulis insignis ad deformitatem puer ("
A notably deformed child shall be killed immediately").
None exemplified this better than the great Stoic philosopher Seneca (c. 4 BC – AD 65):
Or as Plato put it in his
Republic:
Socrates:[9] These two practices [legal and medical] will treat the bodies and minds of those of your citizens who are naturally well endowed in these respects; as for the rest, those with a poor physical constitution will be allowed to die, and those with irredeemably rotten minds will be put to death. Right?
Glaucon: Yes, we’ve shown that this is the best course for those at the receiving end of the treatment as well as for the community. (409e-410a)
Now, most people today in the West would regard such a view as "
immoral" (unless one were trying to relieve someone of unimaginable suffering, as opposed to the Greek view of these persons being worthless or a drain on society) but is it really against
reason? Classical Greece and Rome were eminently
reasonable societies that set a high value upon philosophy and intellectual enquiry. We aren't talking Nazi Germany with its strident anti-intellectualism. Nor were such social norms limited to the Graeco-Roman world. While the ancient Jews did not practise infanticide or eugenics against the weak (and there was a strong Torah-based and prophetic tradition of advocating for the lowly and oppressed against the strong), some Sadducee and Essene Judeans rigidly interpreted the purity laws of the Pentateuch to reach somewhat similar conclusions, as we can see from the
Community Rule at Qumran (dead sea scrolls):
Fools, madmen, simpletons and imbeciles, the blind, the maimed, the lame, the deaf and minors, none of these may enter the midst of the community (CD 15.15-17)
The first century Roman Jewish historian, Josephus, also tells us that at least by his time:
'Anyone who touches or lives under the same roof [with a leper] is regarded unclean' (Contra Apionem 1.281) and that such people were kept away from normal society
(Antiquitates Judaicae 9:74). 'As an attack on the skin [...] leprosy threatens or attacks [...] integrity, wholeness and completeness of the community and its members' (Carter 2000:199; cf. Pilch 1981:113).
And again, on strictly 'rational' grounds....why not? Leprosy was a terrible disease. If lepers are a threat to the community, why not just leave them in a colony somewhere to die with other lepers and keep healthy people safe? The community and its survival comes first, over the welfare of these sick individuals. Many would have seen that as eminently reasonable. Ancient Israel was a society capable of producing great works of wisdom like
Ecclesiastes and
Sirach, with their startlingly astute observations on life. This was not an 'irrational' society in the context of the ancient world - Jews had a reputation among Greeks as a nation of philosophers, an especially philosophical people.
The Greeks and Romans were rational but didn't have a particularly developed notion of innate human dignity, and can we really blame them? The natural order that Aristotle and other natural philosophers saw around them was '
dog eat dog' - predatory animals feasting upon weaker herbivores and characterised by a seeming 'hierarchy' e.g. certain species had 'alpha-males' and such that seemed to naturally privilege males, courtesy of their greater bodily strength, over females.
Likewise, the received customs passed down from the ancestors and believed to originate from the gods themselves, presupposed inherent, natural inequalities between people. There were slaves, and Aristotle took it for granted that some people -
barbarians, those who didn't speak Greek - were 'naturally slaves', born to be subordinated to their betters ("
that one should command and another obey is not just necessary but expedient”). An anecdote attributed to a number of ancient philosophers (including Thales and Socrates) epitomized a principle of the laws of nature many took for a self-evident truth: “
He thanked Fortune for three things: ‘first, that I am a human and not a beast; second, that I am a man and not a woman; third, that I am a Greek and not a barbarian’”. Thucydides, in his history of the Peloponnesian War, would put it even more bluntly than any mere superiority complex: “
The strong do what they have the power to do, and the weak must suck it up”.
Friedrich Nietzsche in the late 19th century and the 20th century eugenicists like Galton, applying Darwinian evolutionary theory to human social relations, deemed this Platonic-Aristotelian-Spartan norm to be the most 'rational' mode of conduct. From the Kaufmann translation of
The Antichrist ss.2 we find that he wrote:
"What is good? - All that heightens the feeling of power, power itself in man. What is bad - All that proceeds from weakness. The weak and ill-constituted shall perish: first principle of our philanthropy. And we shall help them do so. What is more harmful than any vice? - Active sympathy for the ill-constituted and weak - Christianity..."
In 1910, Churchill wrote to the then-British Prime Minister, Asquith, expressing his support for legislation that proposed to introduce a compulsory sterilisation program in the UK, saying: “
The unnatural and increasingly rapid growth of the feeble-minded and insane classes, coupled as it is with a steady restriction among the thrifty , energetic and superior stocks, constitutes a national and race danger which it is impossible to exaggerate … I feel that the source from which the stream of madness is fed should be cut off and sealed up before another year has passed.” Similarly, George Bernard Shaw wrote: "
The only fundamental and possible socialism is the socialisation of the selective breeding of man." Bertrand Russell proposed that the state should promulgate colour-coded "
procreation tickets" to prevent the gene pool of the elite being diluted by inferior human beings.
If we want a healthy, genetically improved human species - what's 'irrational' about it?
Well, its "
immoral" because we empathsize with the poor, innocent souls who are the victims of such policies and believe that they offend deeply-felt humane and intuitive values.