In his epic poem, Lucretius refers to Earth as Mother numerous times, but also takes the time to explain that the personification of Earth as Mother is merely a figure of speech, an act of poetry, and that the planet is not a sentient being as the ancients imagined it to be. The current Gaia hypothesis is a contemporary pseudo-scientific reincarnation of that belief. It is true that beings evolve progressively more complex through symbiotic relationships, but these networks of life do not themselves automatically become separate sentient beings. Here is the relevant passage:
Truly is earth insensate for all time;
But, by obtaining germs of many things,
In many a way she brings the many forth
Into the light of sun. And here, whoso
Decides to call the ocean Neptune, or
The grain-crop Ceres, and prefers to abuse
The name of Bacchus rather than pronounce
The liquor’s proper designation, him
Let us permit to go on calling earth
Mother of Gods, if only he will spare
To taint his soul with foul religion.
– Lucretius, De Rerum Natura, Book II
Later, in the third book, Lucretius delves into the problem of demystifying sentience itself by studying the nature and the physicality of the psyche.