By the time a child is three years old, he can be given a corner of the garden and encouraged to plant seeds in it. When they come up and blossom, his own flowers seem precious and wonderful ; then he can appreciate that his mother's flowers also must be treated with care.
Source: On Education, especially in early childhood, 1926, by Bertrand Russell
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https://russell-j.com/beginner/OE06-030.HTM