That Mark's Gospel is the oldest of the Synoptic Gospels, and that Mark's Gospel does not contain, nor even mention, the Sermon on the Mount. That Luke gives no Sermon on the Mount, but gives what may be called a "Sermon on the Plain." That Luke's sermon differs materially from the sermon given by Matthew. That the Matthew version contains one hundred and seven verses, and the Luke version twenty-nine verses.
Huxley's conclusion is as follows:
"Matthew," having a cento of sayings attributed—rightly or
wrongly it is impossible to say—to Jesus among his materials,
thought they were, or might be, records of a continuous discourse
and put them in a place he thought likeliest. Ancient historians
of the highest character saw no harm in composing long speeches
which never were spoken, and putting them into the mouths of
statesmen and warriors; and I presume that whoever is represented
by "Matthew" would have been grievously astonished to find that
any one objected to his following the example of the best models
accessible to him.
But since Huxley wrote those words more evidence has been produced. From the Old Testament, from the Talmud, and from the recently-discovered Teaching of the Twelve Apostles (a pre-Christian work) the origins of the Sermon on the Mount have been fully traced.
Agnostic criticism now takes an attitude towards this sermon which may
be thus expressed:
1. The sermon never was preached at all. It is a written compilation.
2. The story of the mount is a myth. The name of the mount is not
given. It is not reasonable to suppose that Jesus would lead a
multitude up a mountain to speak to them for a few minutes. The
mountain is an old sun-myth of the Sun God on his hill, and the
twelve apostles are another sun-myth, and represent the signs of
the Zodiac.
3. There is nothing in the alleged sermon that was new at the time
of its alleged utterance.
Of course, it may be claimed that the arrangement of old texts in a new form constitutes a kind of originality; as one might say that he who took flowers from a score of gardens and arranged them into one bouquet produced a new effect of harmony and beauty. But this credit must be given to the compilers of the gospels' version of the Sermon on the Mount.
Let us take a few pre-Christian morals.
Sextus said: "What you wish your neighbours to be to you, such be also to them."
Isocrates said: "Act towards others as you desire others to act towards you."
Lao-tze said: "The good I would meet with goodness, the not-good I would also meet with goodness."