Altan Inigo Soong
Doctor Altan Inigo Soong was a male Human scientist who lived in the 24th century. A self-described "mad scientist", he was the son of Noonian Soong, the creator of the Soong-type androids, and, as such, was the Human "brother" of B-4, Lore, and Data. ()

Biography
After the ban on artificial lifeforms following the Attack on Mars in 2385, Soong and Dr. Bruce Maddox set up a laboratory on Coppelius, the fourth planet of the Ghulion system, where they continued their work despite the synth ban. () 

However, Maddox was convinced that the Federation and other forces were actually responsible for the attack on Mars, and so he created the twin androids Soji and Dahj Asha (through fractal neuronic cloning, based on a positronic neuron recovered from Data and memory fully reconstructed by his Human brother) to discover the truth. Soong, however, believed it would result in unwanted attention, and would lead to their sanctuary being discovered. () 

While Maddox left to set up his own lab, Soong remained behind on Coppelius with the community of androids that he and Maddox had helped create, acting as a surrogate "father" to them. He also created and owned an artificial lifeform that appeared as a cat named Spot II, based on Data's cat Spot. Additionally, Soong had created synthetic butterflies simply because he had missed seeing them. ()

By 2399, Soong had resumed Maddox's research on transferring sentience into an artificial body called a golem, claiming a "sense of urgency". Around that time, Data's former captain, Jean-Luc Picard, had arrived on Coppelius aboard La Sirena to warn that the Zhat Vash, a group of Romulan anti-synth fanatics, were en route with an invasion fleet to destroy them. One of Soong's "daughters", Sutra, who had learned Vulcan techniques such as the mind meld, was able to discover through Maddox's former colleague (and lover) Agnes Jurati that the "Admonition" the Zhat Vash claimed as a warning against synthetics was actually a message from an ancient alliance of artificial lifeforms. The message offered protection against the "oppression" of synthetic lifeforms, even if that meant exterminating all organic life. Hoping to protect his "children", Soong worked with Sutra to build a beacon capable of summoning these protectors. ()

As he worked to perfect his golem, Soong was also attempting to recover the memories of one of his "children", Saga, who had apparently been killed by the Zhat Vash agent Narek during his escape from Coppelius Station. When he accessed Saga's memories, however, he discovered that it was Sutra, aided by Narek, who had killed Saga. He chose to aid the crew of La Sirena in disabling the transmitter, and he himself deactivated Sutra, lamenting that she had been no better than the people trying to destroy her and her siblings. After the Romulan attack was averted, Picard succumbed to a terminal illness that had been diagnosed just before he left Earth. Before Picard's brain functions ceased, however, Soong worked with Jurati and Soji to create a map of Picard's mind and transfer his consciousness into the golem, allowing him to live what years he would have had without his illness.

Informed by the revived Picard that Data wished to have his consciousness terminated as a favor to him, Soong apparently respected his brother's choice. He was a witness along with Jurati and Soji as Picard did so, though not without a note of sadness. ()

Soong's process of transferring a consciousness into a golem would eventually become known as the Soong Method, named after its creator. However, it fell out of use due to a low rate of success. While searching for a way to resurrect Gray Tal in 3190, Doctor Hugh Culber learned about Soong and his golems. Using a combination of the Soong Method and a zhian'tara to unjoin Gray's consciousness from , Gray was successfully resurrected in the form of a golem. ()

Memorable quotes
"I take it my face looks familiar."
"I feel as if I'm looking at Data."
"Data if he had gotten old and gone soft. Must be disturbing. I know it is for me. Doctor Altan Inigo Soong, mad scientist. My father had me, but he created Data – a fact he never let me forget."
- Altan Inigo Soong and Jean-Luc Picard, first meeting ()

"What you did;… shame on you, Agnes. You put out a small, bright candle shedding its light in a vast darkness."
- Soong, to Agnes Jurati, when discussing Bruce Maddox's murder ()

Appendices

Appearances

Background information
Dr. Altan Soong was played by Brent Spiner. According to showrunner Michael Chabon, Spiner came up with the "A.I." initials for the character, as a reference to "artificial intelligence".  Chabon also said Altan Soong was not Juliana's son, but a child from one of Noonien Soong's prior relationships. 

Humans
Scientists