There are different types of issues that confront Orthodox Jews. In this post, I would like to launch a discussion of three categories of such issues.
1. Scientific Issues
...by which I mean issues concerning physical reality. An example would be the topic of the age of the universe. The question of how to treat someone who believes that the universe is billions of years old may be a halachic issue. But the question of the age of the universe itself is clearly, and solely, a scientific issue. An anti-rationalist might insist that the universe is 5771 years old, but he is not denying that it is a scientific issue; rather, he believes that a literal reading of the Torah is a more reliable and authoritative source of information than modern science.
2. Halachic Issues
These are issues which do not involved any determinations about the physical world. An example would be the laws of lashon hara.
3. Scientific-Halachic Issues
These are halachic issues in which the halachic discussion is built upon certain determinations about the physical world. And this is the category that I want to discuss in detail.
One example would be the issue of killing creatures on Shabbos. It's not solely a scientific issue, because the scientific division of life from non-life is not relevant from a halachic standpoint; bacteria are alive from a scientific standpoint, but not from a halachic standpoint. On the other hand, it's not solely a halachic issue, since Chazal made the prohibition contingent on sexual reproduction, and science is used to determine which species reproduce sexually.
Now, here are the two crucial points:
1. It is important to correctly determine whether an issue is a halachic issue, a scientific issue, or a scientific-halachic issue. And the reason for this is as follows:
2. To the extent that a statement utilized in resolving a scientific-halachic issue is based upon a relevant misunderstanding of the physical reality, this undermines the innate validity of the halachic conclusions. This does not necessarily mean that the halachah should be changed; in my book Sacred Monsters, I explained Rav Herzog's view of why there are other reasons to uphold Chazal's ruling about lice, despite it being based upon mistaken science. But, absent such reasons, the halachic conclusions are invalid.
For example, the issue of using electricity on Shabbos or Yom Tov is a scientific-halachic issue. If someone were to make a ruling on this topic based upon a misunderstanding of what electricity is, this would undermine the ruling (to the extent that the misunderstanding is relevant).
Coming up next: A very important application of these principles.