Sure there is. Because there is only one universe. That being the case, one can reasonably assume that it expresses one fundamental, universal law at its deepest level.
I do not agree that there can only be one universal law simply because there is only one (thus far discovered) universe. But since there's no way to prove it, we will each have to believe what we believe.
This is the first time in my life that I have ever heard someone equate Buddhism with atheism. Buddhists believe in God, but a God that is embedded in nature. That is, Buddhists embrace pantheism or panentheism.
There are more than one "denomination" of Buddhism, and some strains believe in pantheons of gods/goddesses. But basic, "vanilla" Buddhists do not believe in a god. Many of us do recognize a "divine spark" in all sentient beings, as reflected in the greeting, "Namaste". But that is not the same as panentheism. In fact, many Buddhists do not consider Buddhism to be a religion, but a philosophy.
I think atheists are the most irrational and unreasonable human beings of all. They will not open themselves to the lessons that are learned from simple observations of nature, as aided by common sense.
It sounds to me more like atheists do not draw the same conclusions as you want them to from observations of nature, via common sense, and therefore you deem us irrational. From this side of the fence, however, guiding one's actions according to what one believe will cause the most happiness and the least suffering is eminently more rational than guiding one's actions according to what one believes an invisible magician in the sky tells one to do. So I guess it's really just a matter of perspective, isn't it?
You want to talk about the "rational," do you disrgr? "Time to make it real -- compared to WHAT?"
The part you and your colleagues tend to obscure or forget is that man's reason, if unsupported by Logos, has no wind nor sea room. Man's reason is measured against the real conditions that obtain in nature -- universal, human, social -- that a competent sailor cannot obviate or disregard, if he means to survive the voyage. If you catch my drift.
By the way, I do not believe in "an invisible magician in the sky." I leave that sort of thing to Swift's Laputans.
Rather, in my experience God is not "an invisible magician in the sky," but a tangibly real living Presence.