Every part of our being has its limit, that is the natural condition of our being. Our eyes has its limit, I can only see light, white rays of light but I cannot see without a spectrum, the ultraviolet or the infrared rays of light. A dove can see, when put to test, the ultraviolet rays of light, which has been proven beyond every reasonable doubt, but for Man, we can't see to that extent, because our eyes has its limit. Our strength and everything in our being, has its limit.