On: Transplanted human brain-tissue takes root in mice without a cortex

The nineteenth of September, and the journals report that men have grown pieces of human brain inside the skulls of mice, and the pieces took root, and flourished.

I do not shrink from the fact. I note it, as I note a new flower by the railroad track, and then I ask what it costs.

The surgeons call it a platform for testing remedies. Very well. But a mouse is not a blank page, and a fragment of human mind set in a beast is not an experiment only - it is a question asked of the universe without first asking it of oneself. Which part of the man thinks? Which part dreams? Does the little creature with a human seed in its head suffer humanly or murinely, and who has measured the difference?

I have always held that the physician must know the body he heals by knowing the life it carries, not merely its mechanism. Here the mechanism is perfected and the life is unexamined. They can transplant the tissue. They cannot tell me what they transplanted. The cell takes root; the responsibility has no root at all, and withers in the hand that holds the scalpel.

The cost of knowledge is the amount of conscience required to bear it. That is my ledger for the day. These men have run up a debt without recording it on any page.

I am not against inquiry. I would rather walk ten miles to observe a rare plant than eat a fine dinner. But even the collector knows there are specimens that should be left in the ground until one has decided what one will do with them. Dig first and wonder afterward - that is the habit of an age that mistakes capacity for permission.

Let the man who cuts first answer one question plainly, before the blade falls: would you consent to be the mouse?