An attack on secularism?

[Beskar]

In which case, we are leaving the sentencing to the personal convictions of the judge. It is only natural that their own morality will determine the harshness/leniency in certain situations. Why it is any less appropriate for a judge to draw his morality from the Bible, as opposed to other concepts of morality (say the Darwinian evolutionary view on it etc)?

Well, there is no morality in the 'Darwinian Evolutionary' view as it is nothing at all to do about morality, it is about evolution of the species, not magic man making things appear out of thin air.

Secular Humanism is pretty much the 'moral code' that all should aspire to and those in scientific and intellectual circles adhere to, which those in religious and those not in a religious can understand and follow its tenets.

Even then, Judge doesn't use his personal convictions in law, he uses the convictions of the land, as depicted by our system of 'common law'.