A simple indicator of the position of sequential thinking in a culture is its insistence on the requirement of consistency. The degree of inconsistency that we note in ancient documents should give us an idea of just how much emphasis that culture placed on reason.
One of the earliest documents to study here is Hammurabi’s laws. These laws contain a number of obvious contradictions, as I explain out in the linked web page. There aren’t many, but those few that exist are, to modern eyes, obvious and almost risible.
Another source lies closer to home: the Bible. Here we encounter a number of inconsistencies. For example, in Genesis, two versions of creation are offered. Genesis 1:1 through 1:31 offers the standard six days of creation, with man created on the last day. But then Genesis 2:4 through 2:7 offer a different version. In this second version, “no shrub of the field had yet appeared on the earth and no plant of the field had yet sprung up” when God made Adam out of the dust of the earth. In the first version, vegetation was created on the second day, and man on the sixth day, but in the latter version, man is created before vegetation.
An astoundingly long list of inconsistencies in the Bible can be found at this page. It covers both the Old and New Testaments. For example, here are two passages concerning the burial of Jacob:
Genesis 50:13
13 For his sons carried him into the land of Canaan, and buried him in the cave of the field of Machpelah, which Abraham bought with the field for a possession of a burying place of Ephron the Hittite, before Mamre.
Acts 7:15-16
15 So Jacob went down into Egypt, and died, he, and our fathers,
16 And were carried over into Sychem, and laid in the sepulchre that Abraham bought for a sum of money of the sons of Emmor the father of Sychem.
One could argue that these inconsistencies arise in different portions of the Bible and so are not egregious. However, there are also flat-out contradictions from the same writer:
Luke 11:9-10
9 And I say unto you, Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you.
10 For every one that asketh receiveth; and he that seeketh findeth; and to him that knocketh it shall be opened.
Luke 13:24
(regarding entry into heaven)
24 Strive to enter in at the strait gate: for many, I say unto you, will seek to enter in, and shall not be able.
or how about this contradiction:
Matthew 10: 1
1 And when he had called unto him his twelve disciples, he gave them power against unclean spirits, to cast them out, and to heal all manner of sickness and all manner of disease.
Matthew 17:14-16
14 And when they were come to the multitude, there came to him a certain man, kneeling down to him, and saying,
15 Lord, have mercy on my son: for he is lunatick, and sore vexed: for ofttimes he falleth into the fire, and oft into the water.
16 And I brought him to thy disciples, and they could not cure him.
Here’s an even better set of contradictions:
John 13:36
36 Simon Peter said unto him, Lord, whither goest thou? Jesus answered him, Whither I go, thou canst not follow me now; but thou shalt follow me afterwards.
John 14:5
5 Thomas saith unto him, Lord, we know not whither thou goest; and how can we know the way?
John 16:5
(Jesus says:) But now I go my way to him that sent me; and none of you asketh me, Whither goest thou?
My point here is not religious in nature: it is that the writers of the Bible were not much concerned with contradictions or inconsistencies; they simply didn’t care much if things didn’t add up rationally.
Looking to Greek civilization, we start with the two oldest documents in Greek literature: the Iliad and the Odyssey. Sure enough, a glaring inconsistency leaps out at us. Fairly early in the Iliad, Pylaimenes, king of the Paphlagonians, is killed. Much later, however, he shows up mourning the death of his son Harpalion. Modern moviegoers or novel-readers, confronted with such a glaring inconsistency, would howl with laughter; the Greeks don’t seem to have noticed the problem. Indeed, there are quite a few inconsistencies in the Homer. However, these are often explained as the result of Homer’s work being essential an oral narrative that was later put down in writing; you can find a partial explanation of the idea here.
But the importance of logical consistency really began to sink in by the time of Socrates. Herewith from The Apology:
Socrates: But now please to answer the next question: Can a man believe in spiritual and divine agencies, and not in spirits or demigods?
Meletus: He cannot.
Socrates: I am glad that I have extracted that answer, by the assistance of the court; nevertheless you swear in the indictment that I teach and believe in divine or spiritual agencies (new or old, no matter for that); at any rate, I believe in spiritual agencies, as you say and swear in the affidavit; but if I believe in divine beings, I must believe in spirits or demigods; - is not that true? Yes, that is true, for I may assume that your silence gives assent to that. Now what are spirits or demigods? are they not either gods or the sons of gods? Is that true?
Meletus: Yes, that is true.
Socrates: But this is just the ingenious riddle of which I was speaking: the demigods or spirits are gods, and you say first that I don't believe in gods, and then again that I do believe in gods; that is, if I believe in demigods. For if the demigods are the illegitimate sons of gods, whether by the Nymphs or by any other mothers, as is thought, that, as all men will allow, necessarily implies the existence of their parents. You might as well affirm the existence of mules, and deny that of horses and asses. Such nonsense, Meletus, could only have been intended by you as a trial of me. You have put this into the indictment because you had nothing real of which to accuse me. But no one who has a particle of understanding will ever be convinced by you that the same man can believe in divine and superhuman things, and yet not believe that there are gods and demigods and heroes.
Here Socrates demonstrates an outright contradiction in Meletus’ accusation against him. On the one hand, this clearly demonstrates his awareness of the fundamental importance of contradiction; on the other hand, the fact that the jury convicted Socrates just as clearly demonstrates that the average Athenian juror didn’t place a lot of importance on such petty things as contradictions.