Benjamin Levin entered a guilty plea for making written child pornography, counselling a person to commit a sexual assault, and possession of child pornography.
The 63-year-old, who was a university professor at the time of his arrest, was originally charged with seven child-pornography-related offences.
In a written statement distributed by his lawyer, Levin said he apologized "unreservedly."
"I am deeply ashamed of these actions and highly aware that they have caused a great deal of hurt," he said. "I am appalled every day that my behaviour fell so far below my own standards and previous actions."
An agreed statement of facts read for the court by Crown prosecutor Allison Dellandrea detailed Levin's proclivity for using an online website with numerous chatrooms for the discussion of sexual activities.
WARNING: CONTENTS MAY DISTURB SOME READERS.
His profile on the site was created in 2010 and indicated his sexuality as "nothing is taboo."
Among the people he chatted with were an undercover officer in Toronto, one in London, Ont., and one in New Zealand — all posing as women interested in sexual activities with children.
The undercover Toronto officer spoke with Levin under two different online personas, court heard.
First, in a conversation beginning in August 2012, the officer said she had two daughters aged 8 and 14.
Levin "normalized and encouraged the sexual touching of the girls by their mother," Dellandrea read from the statement of facts.
In June 2013, the same officer logged into an "incest" chatroom claiming to be a mother attracted to her eight-year-old daughter. In that case, court heard Levin instructed her on how to "groom the child to get her 'used to sex,'" to expose her daughter to pornography, to be nude, and to masturbate in front of the child.
"(She) advised Mr. Levin that she had followed his instructions...that she had sexually assaulted her child," court heard. "Levin instructed (her) to 'play' with this child."
"Mr. Levin stated that it was fine if the child cried and the child should understand that more would be done to her," court heard. "The theme of these discussions was sexualization of the officer's child."
Court heard that Levin didn't think the undercover officer's profile was real. He did not, however, ask or suggest if she or her daughter were fake.
"Nor was it explicitly suggested that their exchanges were intended to be pure fantasy," court heard. "He knowingly counselled (the officer) to sexually assault her daughter."
In his discussions with the undercover officer in London, Ont., in December 2012, court heard Levin expressed further fantasies.
"He said he hoped his daughters would 'share' their own children (his grandchildren) with him and his wife," Dellandrea read.
With the undercover officer in New Zealand, Levin's discussions included him sending over images of females under the age of 18. One depicted a girl in a bondage scene with an adult woman standing over her.
"Levin commented on the photo...'mmm? so hot to imagine a mother doing that to her girl to please her lover,'" court heard.
Other images sent to the officer by Levin included the picture of a crying girl on which he commented "that girl might be crying because she was used somewhat roughly by her mother's lover."
In June 2013, at the New Zealand officer's request, Levin created an online story "detailing the violent sexual assault of a 10 year old child," court heard.
In his chats with the officer, Levin referred to "online chatting as fantasy which is different from reality," court heard.
He never had or sought video chats with the undercover officers or their children, didn't schedule an in-person meeting with them, and never believed he was chatting directly with an underage child, court heard.
Levin was arrested in July 2013 when a search warrant was executed at his home. Police found numerous child pornography files on a digital device.
Police at the time asked any victims of Levin to come forward, but, court heard "to date no one has done so."
Lawyer Clayton Ruby said in a statement Levin believes children need to be protected from exploitation of all kinds and pointed out that his client was not charged with "any actual sexual contact with any person nor with taking any sexual pictures or videos of anyone underage."
Ruby also noted that Levin had "no role" in determining the content of Ontario's recently updated sex education curriculum - a suggestion which has been made by at least one Conservative MP.
From late 2004 to early 2007, Levin held the post of deputy education minister in Ontario, and was on Ontario Premier Kathleen Wynne's transition team as she took office.
He also served as Manitoba's deputy minister of advanced education and deputy minister of education, training and youth between 1999 and 2002.