Science1 has been an immensely powerful tool for revealing the underpinnings of nature and for giving us new ways to meet our needs. However, powerful as science1 is, it has limits. It will serve us best if we ask of it what it does best.
Who am I to discuss these limits? I hold a Ph. D. in cell biology from Brown, practiced cell biology for nearly forty years, held an appointment as a full professor at a Big Ten university, published my age, had six cover photos, and was elected a Fellow of the American Association for the Advancement of Science. Doubtless there are folks here who know more about science than I do, but I know enough to be getting on with the question at hand.Before going further, it is necessary to distinguish two ways that the word "science" is used. One sense refers to the "scientific method," a recursive analytical method that uses what is already known to frame hypotheses, design experiments or observations to test the hypotheses, and then re-evaluate what is known and the truth value of the hypothesis. Lather, rinse, repeat. I'll call this science1. Science1 uses certain assumptions: it assumes that the material universe is all there is, that all phenomena are regular in that they obey either laws or have stochastic patterns, and so on. These assumptions are essential to the method, but clearly are not provable by the method.
A second common meaning of "science" is the world view that holds that the assumptions underpinning science1 are not just useful approximations or working rules, but an actual representation of the world. This world view is sometimes called scientism to distinguish it from the scientific method. I'll call this science2. It's worth noting that science2 or scientism is much older than science1; it is the world view of materialism, and materialism dates back to the Romans and the Greeks, even some would say earlier still.
It's important to note that science1, the method, can't be used to prove science2, the world view. The method can't prove the world view, because it already assumes the key characteristics that science2, the world view, asserts to be true about the universe. People who hold the science2 world view have arrived at that conviction by various routes. Even within materialism, there are multiple flavors of world views. The key point here is that science1 by itself cannot choose a world view; it necessarily uses certain presuppositions about the world and about reason itself.
This distinction between science1 and science2 means that a lab group can have members who are Jewish, Mormon, Christian, Hindu and atheist, all happily applying science1 and making progress together at uncovering some niche of tthe universe because they are all agreed on the method. When the pipettes are put away and the beer has been cracked, they may then talk extensively and even warmly about the ways their world views overlap or contrast. I've had the pleasure of being part of such a lab cluster.
Science1 cannot answer questions of morality. As a method it can (sometimes) tell what is, but morality deals with what ought to be. This gulf is so great that it has a name of its own: the is/ought problem. Ethical systems need to take into account what is known to be factual, but the facts by themselves cannot settle questions of morals.
Science1 can tell us about
and about and things even larger and smaller than these. But science1 cannot tell us how to treat our brothers and sisters, or what the meaning of our own lives is. Those answers must be sought elsewhere.
science1 = scientific method
science2 = scientism, materialism as a world view