If one were to choose among the greatest benefactors of humanity, Louis Pasteur would certainly rank at the top. He solved the mysteries of rabies, anthrax, chicken cholera and silkworm diseases, and contributed to the development of the first vaccines. But in the beginning, he was ridiculed for his theory that diseases were caused by factors that were invisible to the eye. It was a battle to gain acceptance for this theory because many people would not believe that which they could not see.
In the past 200 years, science and technology have made us far more humble regarding that which we cannot see. We now know that we cannot see the overwhelming range of light that makes up the spectrum; we cannot detect the invisible particles that comprise the majority of the matter in the universe. You cannot see the atomic particles that make up the newspaper you are reading, or even the waves, which transmit images and voices to your computer and smart phone. But we have come to believe in and rely upon the invisible.
In our parsha we read about a war with Midian. Jewish soldiers returning from war brought back cooking utensils among the spoils. The Torah reports, “… Eliezer the Priest said to the Soldiers who were going to war, ‘This is the teaching which Hashem commanded Moses … everything which was used with fire shall be purified with fire.’ ” This verse is one of the sources for a law of kashrus. A pot or a knife used for nonkosher food must be kashered before it is used to cook kosher food.
But wait! The verse has Eliezer speaking to “… Soldiers who were going to war.” The soldiers he was addressing had just returned from battle! Perhaps the “war” referred to here is not the physical battle, which they had just concluded. Perhaps there was still a battle to wage within themselves: An internal battle to accept that there was an invisible component affecting the apparently clean vessels taken from the Midianites. Perhaps some of them had yet to fight a battle to accept that an invisible, spiritually damaging component had to be kashered before the vessel could be used.
Sometimes as Jews we also struggle to believe in things our eyes cannot verify. But we have an advantage! Science and technology have accustomed us to accept that there is an entire universe of particles and waves and bacteria that are invisible to the eye, and are very real. Some of these “invisibles” can be of great benefit; some can cause illness or even death.
The Torah is a window into a world that is often invisible and very real. It is a handbook teaching us which actions and objects are of great spiritual benefit and which can cause spiritual illness.
(This column is a service of the Greater Pittsburgh Rabbinic Association.)