投笔从戎
[词典] give up civilian pursuits to join the army; give up literature for a military career; give up [exchange] the pen for the sword; lay aside one's brush and become a soldier;
[例句]从四个层面分析了崇高特征：在人生理想实现中的投笔从戎的慷慨、激越美；
The features can be proved from four perspectives: firstly the beauty lying in passion and generosity in the ideal practice in life;