Years ago I lived in an apartment building in a large city. The building next door was only a few feet away from mine and I could look across the alley into the apartment on the same floor as mine. There was a woman who lived there, whom I had never met, yet I could see her as she sat by her window each afternoon, sewing or reading. 

After several months had gone by, I began to notice that her windows were dirty. Everything was in distinct through her smudged windows. I would say to myself, "I wonder why that woman don't wash her windows?", They look dreadful!"

One bright morning I decided to do my spring house cleaning and thoroughly cleaned my apartment and I washed my windows on the inside. Late in the afternoon when I was finished, I sat down by the window with a cup of coffee for a rest. What a surprise! Across the way, the woman sitting by her window was clearly visible, her windows were clean! 

Then it dawned on me, I have been criticizing her dirty windows, but all the time I was observing them through my own dirty window, that was quite an object lesson for me. How often had I looked at and criticized others through the veil of my own ignorance, through the mist of my own shortcomings? 

Since then, when I have been tempted to pass judgment on someone, I ask myself first, am I looking at him or her through my own dirty window, then I try to polish the windows of my own world so that I may see the world about me with more clarity. 

And do you know? It doesn't look half bad.