Answer

Following receipt of a booklet on Jewish law and reality
Many thanks. It does indeed seem very interesting. Already from the table of contents I have quite a number of comments, but this is not the place. With God’s help, and without making a vow, when I have time I will review this chapter.
Meanwhile, as a token of gratitude to you for sending me your booklet, I will add two small points, even though I only glanced at it for a second; and if you address this later in your remarks, I ask forgiveness.
A. Regarding what you wrote at the beginning of your book, that one should not take notice of something that cannot be seen by the eye, and you based this on the idea that the Torah was not given to ministering angels: in fact one should distinguish between two meanings, and in my humble opinion you did not distinguish between them. 1. Because the creatures in the water are tiny, it is impossible to forbid them, since people need to drink water and cannot filter it. But that reasoning is not based on the fact that the creatures cannot be seen without a magnifying glass; rather, it is based on the fact that there are many of them and they cannot be filtered out. Based on that reasoning, there would also be room to permit a case where the creatures can in fact be seen by the eye, but they are so numerous that they cannot be filtered out—for example, broccoli, where it is hard to filter out the worms even if they are large and visible to the eye. 2. There is also room to permit this on the grounds that instruments are not considered seeing, and that is an entirely different argument. In my opinion, the reason that the Torah was not given to ministering angels is not relevant here at all—what do ministering angels have to do with this? Is it only ministering angels who have assistive devices? I have never heard of an angel using a magnifying glass. Human beings today have instruments, so why should we not be obligated to use them? And is something seen through eyeglasses also not considered seeing? That too is an unnatural device.
B. As for your claim at the beginning of your book against those who object, “Are you setting one man against another?”—I was surprised that someone as distinguished as you would say this, for after all, your own words too are written on the basis of citing sources (the Tiferet Yisrael and others), and not on the basis of your own reasoning alone. If one may cite an authority who agrees with you as support for your view, why should one not be able to cite an authority who disagrees with you as a refutation of your position? This requires further consideration.
Much success and all the best,